Prain v Comcare

Legislation 7 Subject to Pt II of the SRC Act, s 14 of that Act imposes a liability on Comcare to pay compensation in the circumstances for which it provides. In particular, s 14(1) relevantly provides that "Comcare is liable to pay compensation in accordance with this Act in respect of an injury suffered by an employee if the injury results in death, incapacity for work, or impairment". The word "injury" is defined in the SRC Act. 8 By virtue of ss 4(1) and 5A(1), "injury" in the SRC Act means: (a) a disease suffered by an employee; or (b) an injury (other than a disease) suffered by an employee, that is a physical or mental injury arising out of, or in the course of, the employee's employment; or (c) an aggravation of a physical or mental injury (other than a disease) suffered by an employee (whether or not that injury arose out of, or in the course of, the employee's employment), that is an aggravation that arose out of, or in the course of, that employment; but does not include a disease, injury or aggravation suffered as a result of reasonable administrative action taken in a reasonable manner in respect of the employee's employment. The expression "reasonable administrative action" is defined in s 5A(2), but nothing turns on this definition in this case. 9 By virtue of ss 4(1) and 5B(1), "disease" in the SRC Act means: (a) an ailment suffered by an employee; or (b) an aggravation of such an ailment; that was contributed to, to a significant degree, by the employee's employment by the Commonwealth or a licensee. 10 Subsection 5B(2) further provides that: In determining whether an ailment or aggravation was contributed to, to a significant degree, by an employee's employment by the Commonwealth or a licensee, the following matters may be taken into account: (a) the duration of the employment; (b) the nature of, and particular tasks involved in, the employment; (c) any predisposition of the employee to the ailment or aggravation; (d) any activities of the employee not related to the employment; (e) any other matters affecting the employee's health. This subsection does not limit the matters that may be taken into account. 11 Subsection 5B(3) states that in the SRC Act: significant degree means a degree that is substantially more than material. 12 The word "ailment" is defined in s 4(1) to mean: any physical or mental ailment, disorder, defect or morbid condition (whether of sudden onset or gradual development). 13 Section 16 of the SRC Act provides for compensation in respect of medical expenses. For present purposes, it is sufficient to refer to s 16(1), which reads: Where an employee suffers an injury, Comcare is liable to pay, in respect of the cost of medical treatment obtained in relation to the injury (being treatment that it was reasonable for the employee to obtain in the circumstances), compensation of such amount as Comcare determines is appropriate to that medical treatment. 14 Section 19 concerns compensation for injuries resulting in incapacity. The provision "applies to an employee who is incapacitated for work as a result of an injury, other than an employee to whom section 20, 21, 21A or 22 applies": s 19(1). It is unnecessary to refer to the remainder of s 19, which sets out how the compensation is to be calculated, "for each week that is a maximum rate compensation week during which the employee is incapacitated".

Issues before the Tribunal 15 Although Comcare accepted in the Tribunal proceedings that Mrs Prain continued to suffer psychological symptoms, Comcare maintained that Mrs Prain no longer suffered from the adjustment reaction that had given rise to her previously accepted claim for compensation for that condition. Comcare argued that Mrs Prain had ceased to suffer from this condition at some point prior to 16 July 2015. In this context, the Tribunal stated that it was required to determine four issues: Tribunal reasons at [11]. These issues were: (a) Is Mrs Prain's psychiatric condition [adjustment reaction] an injury (other than a disease) or a disease pursuant to s 5A of the [SRC] Act? (b) Does Mrs Prain continue to suffer from a work-related condition? (c) If so, has she suffered any impairment as a result of the condition, and is the impairment permanent? (d) If so, what compensation, if any, under Part II, Division 4 of the [SRC] Act is she entitled to? (Emphasis in original.) The Tribunal accepted that in "a practical sense", Comcare was required to explain the existence and cause of what were Mrs Prain's psychological symptoms after 16 July 2015: Tribunal reasons at [12].

Mrs Prain's psychiatric condition was a disease 16 The Tribunal found that Mrs Prain suffered a disease arising from her employment at the Canberra Hospital: Tribunal reasons at [21]. After referring to numerous authorities, including the decision of the High Court in Military Rehabilitation and Compensation Commission v May [2016] HCA 19; 257 CLR 468 (Compensation Commission v May), the Tribunal said (at [20]): It should be noted, of course, that the condition under consideration in May was a physical, not a psychological, condition. In this sense, the authority which Mr Anforth [counsel for Mrs Prain] was seeking, to clarify precisely in what circumstances a psychological condition qualifies as an injury, is not provided by the High Court here. However, in overturning some of the reasoning of the Federal Court and in emphasising the continued utility of sudden or identifiable physiological change in the normal functioning of the body as the touchstone for injury, I regard the High Court's decision as affirming the long line of authorities which have tended to place mental illness in the statutory category of disease. The Tribunal has in mind, in particular, the words of Drummond J in [Comcare v] Mooi [(1996) 69 FCR 439] at (443-4): But in my opinion, the expressions used in the [SRC Act] to define the various forms of mental condition that can amount to "injuries" compensible under s 14(1), do not appear to be used in any technical medical sense, but have the meanings they bear in ordinary usage. It follows, in my opinion, that, so far as events that do not result in any physical harm to a worker or in the development of any observable pathology in the worker's body but which only have some form of psychological consequence are concerned, the worker will be able to show the existence of a mental ailment, disorder, defect or morbid condition even though his resultant condition cannot be identified with the label of a recognised medical condition. (Emphasis in original.)

The evidence before the Tribunal about Mrs Prain's mental state 17 The Tribunal turned to the evidence about Mrs Prain's mental condition, after noting that "Comcare acknowledged Mrs Prain's dysfunctionality, but argued that, after five years, the events of April 2011 at the Canberra Hospital had diminished in significance and impact on Mrs Prain's illness, that other adverse events in her life were now contributing significantly to her depressed state and that there was, in any case, a degree of exaggeration in the intensely-focused attribution of her condition on those events in Canberra": Tribunal reasons at [22]. 18 At [23] to [41] of its reasons, the Tribunal set out its understanding of the key points of the lay evidence (including that of Mrs Prain and her husband) and the medical and psychological evidence (including that of Dr John Saboisky, Mr Roger Lurie, Dr David Bell and Dr Ross Whittaker) about Mrs Prain's mental condition. 19 It suffices to note at this point that the Tribunal accepted (at [23]) that the evidence of Mrs Prain contained "ample demonstration that she suffers from a psychiatric disorder of some severity". After referring to Mrs Prain's account of what happened to her during her employment at the Canberra Hospital, however, the Tribunal also stated (at [25]) that: [T]he acts of fellow workers which disrupted her psychological well-being might fairly be described as nothing out of the ordinary: offhand comments, unkind words, ill-considered administrative mechanisms, insensitivity to Mrs Prain's needs and feelings, but certainly nothing dramatic or shocking in an empirical sense. 20 The Tribunal also referred to Mrs Prain's evidence about her mental condition in April 2011 and more recently, the aggravation of other medical conditions, and the breakdown of family relationships.

Did Mrs Prain continue to suffer an ailment? 21 The Tribunal drew on some of this evidence to confirm its finding (at [42]) that Mrs Prain's adjustment reaction was a disease and that her employment contributed to a significant degree to that ailment in 2011. It identified (at [43]) the issues that arose from this finding as follows: Accordingly, in reviewing Comcare's decision to discontinue her entitlement to compensation, the Tribunal must consider, as at 16 July 2015, (a) whether Mrs Prain continued to suffer an ailment and (b) whether the circumstances of her employment in 2011 were still contributing, to a significant degree, to that ailment. If the answers to both these questions are yes, the Tribunal should then consider whether her employment continues to contribute to a significant degree to her ailment. 22 The Tribunal treated the evidence of Mrs Prain as significant in determining whether, as Comcare submitted, other events in her life since April 2011 had "crowded out" what had occurred at the Canberra Hospital or, as said on Mrs Prain's behalf, most of the other post-April 2011 factors were secondary or derivative from the principal work-related cause: Tribunal reasons (at [44]). The Tribunal set out Mrs Prain's evidence in some detail, stating (at [46]) that it was "troubled by some incongruities" in her evidence and in her demeanour as a witness, as well as noting (amongst other things) that there were contradictions in her evidence; that her evidence regarding her husband did not "seem consistent with the contemporaneous records of her clinical advisers" (at [48]); that her explanation about a letter shown to her General Practitioner, Dr Colpo, in March 2015 did not sit easily with her statement that she trusted Dr Colpo; and that her explanation about a list she said was written at Mr Lurie's request was inconsistent with Mr Lurie's evidence and her claim that her state of mind arose from the events at the Canberra Hospital: Tribunal reasons at [46]-[59]. 23 Further, the Tribunal stated (at [59]) that it faced "a strange dichotomy", namely: On the one hand Mrs Prain, a woman afflicted by severe mental illness, professed great equanimity and composure in the face of tribulations - her husband's infidelity, estrangement from her children, car accidents, debilitating pain - that would likely have taken a toll on the healthiest person. On the other hand, she told Dr Bell Life can never be the same for me again after what appeared to be relatively unexceptional occurrences over the course of one week in her workplace. The Tribunal found (at [59]) that "there was a considerable element of exaggeration in the claims put by Mrs Prain and that, in particular, the other setbacks in her life had a greater impact on her mental well-being than she was prepared to concede". 24 Notwithstanding these statements about her evidence, the Tribunal acknowledged that Mrs Prain was "entitled to succeed if the compensable factors have nonetheless contributed to that injury to a significant degree". It therefore turned to consider "the evidence as a whole", "including evidence independently corroborative of her claim - to establish what weight should be assigned to the compensable and non-compensable factors respectively": Tribunal reasons at [60]. 25 In this context, the Tribunal found (at [61]-[62]) that "anxiety derived from her litigation with Comcare has played a role in her disorder"; and that this anxiety was "linked with a need for vindication". Citing Australian Telecommunications Commission v Tzikas (1985) 5 AAR 173 at 195 and Plumb and Comcare [2004] AATA 999, the Tribunal did not apparently accept these factors as a basis for compensation, observing (at [63]): Reactions - or indeed overreactions - to events in the workplace, if they are properly regarded as sequelae of an applicant's employment, are part and parcel of the original injury, but it is well established that anger and frustration towards a respondent in resolving a legal claim for that injury is not. 26 The Tribunal continued (at [65]): Since the decisions in [Australian Telecommunications Commission v] Tzikas [(1985) AAR 173] and Plumb [and Comcare [2004] AATA 999] the [SRC] Act has been amended to require a stronger connection between an employee's employment and a disease which it is claimed that employment gives rise to. Consideration of this question now requires an examination of the factors set out in s 5B(2). It was put to the Tribunal by Comcare that, in the present case, two paragraphs are particularly relevant to Mrs Prain: (a) the duration of the employment… (c) any predisposition of the employee to the ailment or aggravation In this context, the Tribunal notes the relatively short period (three months) of Mrs Prain's employment at the Canberra Hospital prior to the events in question, and the evidence suggesting a possible heightened susceptibility on her part to the kind of injury she sustained at the hospital: • both psychological problems and fibromyalgia predating her employment at the hospital (though she was not currently suffering from either problem at the time she commenced that employment); • the observation by Dr Saboisky that many people suffering a chronic pain disorder also suffer from depression; • personality traits predisposing her to reacting adversely to relatively minor stresses. Counsel for Comcare cited her distress at what a clairvoyant had said to her as an example of this. 27 The Tribunal concluded (at [66]) that "the effect of the relevant factors in s 5B(2) must be to diminish to some degree the weight attached in this case to the Canberra Hospital issues vis-à-vis other issues contributing to her mental disorder". 28 Turning to the medical evidence, the Tribunal stated (at [67]-[68]): The medical evidence bearing on these issues is not uniform in what it suggests. Dr Saboisky told the Tribunal that half of the reason for Mrs Prain's depression was her Canberra Hospital experience and half was her concerns with her marriage. Dr Bell opines that there is no work contribution because there is no adjustment disorder. Her psychologist, Mr Lurie, offered the view that the issues at the Canberra Hospital were the trigger… in that they lead to the core sense of herself being violated, and that therefore they were a factor in the other issues with which she presented. For its part, the Tribunal assesses the truth to lie somewhere between these positions. Mrs Prain began to see her psychologist, Mr Lurie, in 2011 after the incidents at the Canberra Hospital. He gave evidence about his consultations with her for the period until 2015, and his clinical notes from that time were tendered. The notes make reference to a wide range of issues which she raised with him in those consultations. These included management of her pain, issues surrounding her litigation with Comcare and family issues including issues with her marriage, but are largely devoid of reference to the incidents at the Canberra Hospital after the end of 2012. (Emphasis in original.) 29 Ultimately, the Tribunal concluded (at [70]) that, on the basis of the evidence, Mrs Prain's employment at the Canberra Hospital had ceased to be a significant contributor to Mrs Prain's adjustment disorder by July 2015. 30 Mrs Prain's case was that if this claim failed, then so did her claim for permanent impairment and non-economic loss under ss 24 and 27 of the SRC Act. Accordingly, the Tribunal also affirmed Comcare's decision of 27 November 2013.

Appeal under s 44 of the AAT Act 31 The appeal raised the question, whether or not the Tribunal misconstrued and misapplied Compensation Commission v May when it concluded that Mrs Prain's adjustment reaction was a "disease" for the purposes of s 5B(1) of the SRC Act. The appeal also raised the question whether or not the Tribunal misunderstood and misapplied the tests of causation to which s 5B(1) of the SRC Act gave rise. 32 Senior Counsel for Mrs Prain, Mr Kennett SC, noted that, at [43] of the Tribunal's reasons, the Tribunal framed the questions before it as at 16 July 2015: (a) whether Mrs Prain continued to suffer an ailment; and (b) whether the circumstances of her employment in 2011 were still contributing, to a significant degree, to that ailment. Mr Kennett submitted that in principle, the questions were to be answered as at the time the Tribunal made its decision, not at some earlier time. Counsel for Comcare responded, however, that, bearing in mind the circumstances in which Mrs Prain came to make her claim, there was no error in this regard. Since Mr Kennett did not maintain that there was any separate error arising from any mistaken identification of the relevant date, this issue may be put to one side.

The questions of law 33 Mrs Prain appealed on three questions of law, namely: 1. Did the Tribunal err by proceeding on the basis that a mental illness such as adjustment disorder could not constitute an "injury (other than a disease)" within section 5A of the [SRC Act]? 2. Did the Tribunal err by proceeding on the basis that a "sudden and ascertainable or dramatic physiological change" was a necessary element of an "injury (other than a disease)" in section 5A of the [SRC Act]? 3. Did the Tribunal misapply section 5B(1) of the [SRC Act] by finding its test not satisfied on the basis that subsequent stressors have "push[ed] the employment factor further and further into the background", without analysing the extent to which the original work-related ailment affected the claimant's reaction to those stressors?

Causation 34 At the hearing of the appeal, Mr Kennett SC submitted that the Tribunal did not really deal with Mrs Prain's submission that the events that Comcare said had "crowded out" the events at the Canberra Hospital as "the major contributors" to her mental ill-health were in fact "secondary or derivative from the principal work-related cause" (i.e., "the disruption to her core values and sense of self-worth occasioned by what occurred at the Canberra Hospital"): see Tribunal reasons at [44]. 35 Senior Counsel for Mrs Prain further submitted that the Tribunal did not address the question that arose under s 5B of the SRC Act, which was whether or not Mrs Prain's adjustment reaction "was contributed to, to a significant degree, by" the events at the Canberra Hospital. Her submission before the Tribunal had been, and remained, her "anxiety about Comcare" might be seen as "the ongoing manifestations of a mental state ... disturbed by earlier events". Senior Counsel further submitted that the Tribunal adopted an incorrect approach with respect to s 5B(2), since it was not correct "to look for different factors and to weigh them", as the Tribunal apparently did, in determining whether an ailment was contributed to, to a significant degree, by the employment in question. Rather, so he said, "it's a question of contribution and significance and not a question of the weight of one factor compared to other factors". In this context, it was said that the fact that Mrs Prain had worked at the Canberra Hospital "for a fairly short time" was "not something that logically goes against her case". 36 Senior Counsel for Mrs Prain challenged the Tribunal's statement (at [70]) that "most of the factors which the medical records suggest were agitating the applicant after April 2011" were "novus actus interveniens" and had the effect of "pushing the employment factor further and further into the background", so that her employment ceased to be a significant contributor to the adjustment reaction by July 2015. Mr Kennett SC submitted that, in reaching this conclusion, the Tribunal did not grapple with Mrs Prain's case that the later events in her life were "precipitated by her altered personality or disturbed mental state, or if her reaction to those events was a product of her disturbed mental state"; and if so, that the factor that caused her disturbed mental state (her employment) remained "causative to a substantial degree". Senior Counsel submitted that the Tribunal needed to decide the extent to which Mrs Prain's later difficulties were "the product of a mental state that had been disturbed by her employment experience", in order to deal with the case that Mrs Prain advanced. 37 In this latter context, Mr Kennett SC drew attention to the terms of s 19(1) of the SRC Act, pursuant to which s 19 applied to an employee incapacitated for work "as a result of an injury". Mr Kennett SC submitted that: [I]t had been accepted that the applicant suffered from the adjustment disorder and that that was caused, in the requisite sense, by her employment. So the question that section 19 required to be asked was whether she was incapacitated and whether the incapacity was a result of that ailment, which doesn't necessarily require her still to be suffering the same way [from] it. ... But the more correct question, in the light of section 19, is what's the current incapacity and can one trace the source of that back to the injury that was accepted to have occurred? The Tribunal, we say, hasn't done it that way. It gives rise to, I suppose, much the same sorts of complaints about causation analysis, but we would once again say whether her incapacity relates from the accepted injury is not something that can be answered by weightings or notions of background. It's something that requires asking whether there's a substantial causal chain that leads from one to the other. So the question is whether she is incapacitated currently by the original injury, including by any natural or ordinary consequences of it.

Mental illness may be an injury or a disease 38 With respect to whether the adjustment reaction was necessarily a disease, Mr Kennett SC noted at the outset that it was put to the Tribunal that, if not compensable as a disease, the applicant's condition was compensable as "an injury (other than a disease)" : see s 5A(1)(b). He noted that if a condition was not a disease, it might still be an injury, within the meaning of s 5A(1)(b) of the SRC Act in the sense of a mental injury arising out of, or in the course of, the employee's employment. Senior Counsel accepted that, in order for there to be an injury, there must be an identifiable psychological change, as opposed to physiological change. At the hearing, he said: We would submit that a mental injury might be found in a set of psychological symptoms, as long as they have the requisite medical recognition and perhaps specificity, even though one might not be able to identify a physical chemical or physical origin for those symptoms. ... [W]e accept, distinct or identifiable change to the body or the mind for the worse, in order for there to be an injury. 39 Mr Kennett SC submitted that the Tribunal misunderstood Compensation Commission v May by treating the formulation, "a sudden and ascertainable or dramatic physiological change or disturbance of the normal physiological state" in Kennedy Cleaning Services Pty Ltd v Petkoska [2000] HCA 45; 200 CLR 286 (Kennedy Cleaning) at [39] (Gleeson CJ and Kirby J) as constituting the "test for injury". It was, so he submitted, a mistake to include a notion of "suddenness" or "dramatic moment" in the test for injury. He argued that the Tribunal's misunderstanding of the test for injury was reflected in its related statement (at [42]) that "there was no single, definable moment or moments during [the] period when Mrs Prain might be said to have sustained a change or disturbance - of the kind referred to by their Honours in Kennedy Cleaning - amounting to a psychological injury". Senior Counsel for Mrs Prain submitted that this error made a difference because the evidence on which Mrs Prain relied would have been sufficient "to support a finding that she had suffered a distinct or identifiable change in her mental state in the course of that week or so". 40 Also with reference to Compensation Commission v May, Mr Kennett SC took issue with the Tribunal's statement, at [20] of its reasons, that "in overturning some of the reasoning of the Federal Court and in emphasising the continued utility of sudden or identifiable physiological change in the normal functioning of the body as the touchstone for injury, I regard the High Court's decision as affirming the long line of authorities which have tended to place mental illness in the statutory category of disease" (emphasis in original). Senior Counsel submitted that this did not follow from what was said in Compensation Commission v May and the decision should not have been read in this way by the Tribunal. He submitted that the dichotomy between "injury" and "disease" that the Tribunal drew, at [20] of its reasons, was the wrong dichotomy to draw in the context of the relevant statutory provisions.

The adjustment reaction as "an injury (other than a disease)" 41 In written submissions filed before the hearing, Mrs Prain put the point in this way: The conclusion at [42] that the condition suffered by the applicant "was a disease" is not in itself erroneous; indeed, it was accepted by the respondent until its decision on 16 July 2015 that the applicant suffered a "disease" as defined in s 5B. However, the Tribunal's route to that conclusion (the onset was not sudden, therefore it is not an "injury", therefore it is a "disease") betrays a misunderstanding of the network of definitions as noted above. The error is significant because if (as the Tribunal held) the applicant's condition is no longer contributed to, to a significant degree, by her employment (and is therefore not a disease as defined), the proper analysis requires consideration of whether her condition comes within s 5A(1)(b). The Tribunal's error foreclosed consideration of that question. Properly applying the reasoning of the Chief Justice and Kirby J in Kennedy Cleaning, an adjustment reaction with mixed emotional features is a disturbance of the normal psychological state that will constitute a mental injury in the primary sense. (Citation omitted; emphasis in original.) 42 Senior Counsel for Mrs Prain submitted that the statutory dichotomy was between "disease" (as defined) and "injury [as defined] other than disease" (cf: s 5A(1)(a) and (b)). He submitted that: [T]he Tribunal misunderstood that feature of the structure of the [SRC] Act and missed that further question, or didn't reach that further question which we say is critical, namely, is this within 5A(1)(b)? And its reasoning is tainted by an underlying notion or assumption that something which is a disease in some ordinary sense, that is an ailment, is ipso facto not an injury in the 5A(1)(b) sense. 43 It was submitted that the error was manifest in features of the Tribunal's reasons, including in the heading, "Is Mrs Prain's psychiatric condition an injury or disease?", as well as in [13], [15], [20] (where the Tribunal stated "I regard the High Court's decision as affirming the long line of authorities which have tended to place mental illness in the statutory category of disease") and [21] (where the Tribunal held that Mrs Prain suffered a disease arising from her employment at the Canberra Hospital). With respect to that conclusion, Senior Counsel for Mrs Prain said: [T]he conclusion that she suffered the disease is unproblematic, but it's put here as an answer to an argument to the effect that it's now a compensable as an injury other than a disease.

The adjustment reaction as "an injury (other than a disease)"; mental illness may be an injury or a disease 44 In written submissions filed before the hearing, Comcare contended the terms "disease" and "injury (other than a disease)" may lead to overlapping bases of liability but the terms have different work to do; and "in respect of a 'condition' which answers the description of a psychiatric disease, an employee must be able to point to some distinct change or disturbance to his or her psyche or mind (separate to the disease state) which constitutes a mental injury (in the primary sense)". Comcare submitted that the text, structure and evident purpose of the relevant statutory provisions indicated that the legislature intended that there would not be a large area of overlap between what constitutes an "ailment" and an injury simpliciter; and that the legislature contemplated that injuries simpliciter would normally occur within a relatively short and finite period of time, that both the time and place at which the injury occurred would be readily identifiable, although it would often be impossible to say precisely when, or where, an "ailment" was contracted. Citing Canute v Comcare [2006] HCA 47; 226 CLR 535 at [10] and Hume Steel Ltd v Peart [1947] HCA 34; 75 CLR 242 (Hume Steel) at 251, Comcare submitted that; The SRC Act draws a clear distinction between 'an injury' (in its statutorily defined sense, as opposed to an injury simpliciter) and what results from 'an injury'. When determining whether 'an injury' has been suffered (including whether there was 'an ailment' or an injury simpliciter) the focus should therefore be on the change to the body or mind that has resulted in symptoms rather than on the symptoms or results themselves. (Citations omitted.) 45 Comcare referred to s 6 of the SRC Act, which relates to an injury (other than a disease), and contended that "the provisions of s 6 clearly contemplate an employee 'sustaining' an injury simpliciter within a relatively short and finite period of time. They also all contemplate that both the time and place at which the injury occurred are identifiable". This was to be contrasted with s 7, a deeming provision operating with respect to diseases, which recognised that diseases will often develop over a long period of time. Comcare submitted: Section 7(4) of the SRC Act deals expressly with when, in point of time, an employee shall be taken to have sustained a disease (or aggravation thereof). It is predicated on a legislative recognition that, absent such a provision, it would often be impossible to say when, in point of time, an ailment is contracted. The absence of any equivalent provision in relation to injuries simpliciter suggests the legislature did not anticipate the same sort of difficulty would arise in relation to injuries simpliciter. The presence of a 'temporal limb' as a means of establishing liability for an injury simpliciter and the absence of such a limb, as a means of establishing liability for 'an ailment', is a further indication of a contemplation on the part of the legislature that when an injury simpliciter is suffered will be identifiable but when 'an ailment' is suffered will often not be. 46 Citing Australian Postal Corporation v Burch [1998] FCA 944; 85 FCR 264 (Burch) at 268 and Compensation Commission v May at [71]-[72], Comcare further submitted that, since the word "disease" was defined and the expression "injury (other than a disease)" was not, the latter bore its ordinary meaning of "getting hurt rather than becoming sick": see Hume Steel at 252 (Latham CJ) and Zickar v MGH Plastic Industries Pty Ltd [1996] HCA 31; 187 CLR 310 (Zickar) at 332 (Toohey, McHugh and Gummow JJ). Comcare contended that the general formulation of the occurrence of physical or mental injury in Compensation Commission v May at [52] was not limited to particular factual scenarios. Comcare contended that: [T]he plurality intended the issue of whether a physical or mental injury simpliciter had occurred should be determined by (i) firstly, focusing on the nature and incidents of the changes/disturbances to the body (including the mind) at play, and (ii) secondly, recognising that where the nature and incidents of the physiological/psychological change(s) do not enable identification of some sudden and ascertainable or dramatic change within the body, mind or psyche of the employee, an injury simpliciter will generally not exist. The same approach, but with an even greater emphasis on the need for a sudden or identifiable change to the physical or mental functioning of the mind or body, was suggested by Gageler J. (Citations omitted.) 47 At the hearing before this Court, Comcare addressed the questions relating to these issues together. As to whether mental illness may be an injury or a disease, counsel for Comcare submitted: [W]hen fairly read, [the Tribunal's approach was] entirely consistent with the text, structure and purpose of the relevant productions of the [SRC] Act and the authority that was binding on the Tribunal and this Court. And the Tribunal asked itself the right question, and approached its answer to that question in an appropriate way, and therefore its conclusion was open to it. 48 As to whether the Tribunal properly considered whether the adjustment reaction was "an injury (other than a disease)" for the purposes of s 5A(1)(b) of the SRC Act, counsel for Comcare submitted that: [A] fair reading of the Tribunal's reasons as a whole shows that rather than treating the two categories as mutually exclusive and, for example, reasoning because it was an ailment, and therefore a disease, it couldn't have been an injury, the Tribunal carefully considered whether it was an injury other than a disease and found that it was not. 49 Referring to [13] of the Tribunal's reasons, counsel for Comcare emphasised that the Tribunal was aware that it was part of Mrs Prain's case that "the adjustment disorder was a paradigm case for mental injury not a disease and that suddenness was an irrelevant consideration". Counsel submitted that, at [18], the Tribunal showed its correct understanding of Compensation Commission v May, and at [20], its understanding that "suddenness" was not an element in the definition of "injury". 50 Counsel for Comcare submitted that "the Tribunal's reference to the long line of authorities [including Comcare v Mooi [1996] FCA 508; 69 FCR 439 (Comcare v Mooi)] which have tended to place mental illness in the statutory category of diseases [was] an appropriate factor to take into account". This was because the authorities reflected that "the ordinary understanding or meaning of the words such as 'injury, ailment, disease' do bear out the words of Latham CJ in Hume Steel [see 252] that an injury is tantamount to getting hurt and an ailment or a disease is tantamount to becoming sick". In written submissions, Comcare noted that there was "a line of authorities that have characterised an adjustment disorder as an ailment, rather than an injury simpliciter". 51 It was submitted that, in a case like the present one, the Tribunal made the correct inquiry, namely: [W]as the nature and incidents of the change that occurred to the applicant in a relevant period such that properly fits the characteristics of an injury simpliciter or an ailment or both? 52 In this context, Comcare submitted that [21] and [42] of the Tribunal's reasons did not give rise to the difficulties that Mr Kennett SC suggested. Comcare emphasised that [21] expressed a conclusion referrable to "the reasons set out below" as well as the principles to which the Tribunal had already referred. The "reasons set out below" culminated in [42], and showed that the Tribunal approached its task in accordance with what was said by the High Court in Compensation Commission v May, because it considered "the nature and incidence of exactly what happened". In this connection, Comcare referred to [24] and [25] of the Tribunal's reasons and the Tribunal's subsequent account of the medical and psychological evidence. Counsel submitted that [42] showed that the Tribunal "could not identify any sudden ascertainable or dramatic physiological change or disturbance" and "implicitly, rejected the argument that had been advanced that this condition was an injury simpliciter and found, expressly, that it was an ailment and in light of the concession made, therefore, a disease".

Causation 53 Counsel for Comcare submitted that the Tribunal, at [44] to [69], carefully analysed the relevant evidence in answering the question that s 5B required the Tribunal to answer, which the Tribunal had correctly stated at [43]. Comcare submitted that the conclusion that the Tribunal came to at [70], "that each - or at least most - of the factors which the medical records suggested were agitating the applicant after 2011 had the effect of pushing her employment further and further into the background - such that employment had ceased to be a significant contributor to her adjustment disorder by July 2015 - is entirely consistent with the question s 5B required the Tribunal to answer". The Tribunal was not, Comcare submitted, required to answer the "but for" test that Mrs Prain suggested. 54 At the hearing before this Court, in respect of the question of causation, counsel for Comcare contended that: [I]n relation to the way the case was argued or run by the applicant in the Tribunal, the Tribunal was fully entitled to approach the matter, although it did mainly decide whether the applicant had initially suffered from an injury simpliciter or a disease, and then treat that finding as informing its consideration of the position as at the cease of next date in 2015. Counsel for Comcare submitted that it came down to "whether the ongoing adjustment disorder after 16 July 2015 [was] a continuation of the adjustment disorder before that date". That was the case that Mrs Prain mounted before the Tribunal, and the Tribunal dealt with and rejected it at [68] to [70]. Comcare submitted that there could be no error in the Tribunal not considering a matter that was not put to the Tribunal for consideration, citing Cao v Secretary, Department of Families, Housing, Community Services and Indigenous Affairs [2014] FCA 52 at [35]; Re Minister for Immigration and Multicultural and Indigenous Affairs; Ex parte Applicants S134/2002 [2003] HCA 1; 211 CLR 441 at [31]-[32]; and Commissioner of Taxation v Glennan [1999] FCA 297; 90 FCR 538 at [82].

Grounds 1 and 2 55 Grounds 1 and 2 cover much the same ground. By these two grounds, Mrs Prain asserted that the Tribunal had erred "in proceeding on the basis that a mental illness[] constituted a 'disease' and therefore not an 'injury (other than a disease)'" and "in treating 'sudden and ascertainable or dramatic physiological change' as the test for an 'injury (other than a disease)' in s 5A(1)(b)" of the SRC Act. 56 Mrs Prain claimed an entitlement to compensation in respect of her adjustment reaction under s 19 of the SRC Act, on the basis that she was incapacitated from work as a result of an injury suffered by her at the Canberra Hospital in 2011. As we have seen, Comcare's position was that it was not liable to compensate Mrs Prain in respect of the adjustment disorder after 16 July 2015, although it had accepted liability in respect of the earlier period. As we have seen, the Tribunal affirmed Comcare's decision to this effect. 57 In support of her claim, Mrs Prain's case focussed on the existence of an "injury", being "an injury (other than a disease)" as referred to in s 5A(1) of the SRC Act. As noted, "injury" is relevantly defined in s 5A(1) of the SRC Act to mean: (a) a disease suffered by an employee; or (b) an injury (other than a disease) suffered by an employee, that is a physical or mental injury arising out of, or in the course of, the employee's employment; or (c) an aggravation of a physical or mental injury (other than a disease) suffered by an employee (whether or not that injury arose out of, or in the course of, the employee's employment), that is an aggravation that arose out of, or in the course of, that employment; ... 58 Referring to the definition of "injury" in s 4(1), which was in relevantly the same terms as the present s 5A(1), French CJ, Kiefel, Nettle and Gordon JJ explained in Compensation Commission v May 257 CLR 468 at [42]-[44]: The set of conditions answering the definition of "injury" in the Act relevantly comprises two sub-sets, "disease" and "injury (other than a disease)", the latter sometimes referred to, not necessarily helpfully, as injury simpliciter. They comprise separate but related bases of liability. Each has a different meaning in the statutory scheme. As appears from the definition of "disease", a "disease" for the purposes of the Act must be an ailment or an aggravation of an ailment. That is not sufficient to establish the existence of a disease. The ailment or aggravation thereof has to have been contributed to in a material degree by the employee's employment by the Commonwealth. An "injury (other than a disease)" covers the other sub-set of "injury". Various aspects of this limb of the definition of "injury" should be observed. First, the phrase "other than a disease" means that if an employee establishes that they have a "disease" within para (a) of the definition of "injury", there is no need to consider para (b). Second, an "injury (other than a disease)" suffered by an employee must be "a physical or mental injury arising out of, or in the course of, the employee's employment" (emphasis added). That is to say, the physical or mental injury has to have a causal or temporal connection with the employee's employment. (Citations omitted.) 59 Referring to the different statutory inquiries relevant to "disease" and "injury (other than a disease)", their Honours emphasised (at [56]) "the importance of the distinction drawn by the Act between 'disease' and 'injury (other than a disease)' in the definition of 'injury' in s 4(1) of the Act" and noted that the distinction "recognises that each creates a different basis for liability under the statutory scheme". On the one hand, the definition of "disease" in s 5B(1) of the SRC Act requires that, for the purposes of the SRC Act, a "disease" must be an ailment or an aggravation of an ailment; and that ailment or aggravation must have been contributed to, to a significant degree, by the employee's employment by the Commonwealth or a licensee. That is, the SRC Act requires "a higher level of work connection in the case of a disease" to attract liability: see Burch 85 FCR 264 at 268. On the other hand, an "injury (other than a disease)" must be "a physical or mental injury arising out of, or in the course of, the employee's employment". That is, in the case of an injury "in the primary sense" (also called an "injury simpliciter") liability depends on a lower level of causal or temporal connection with the employee's work. 60 At the general level, as Latham CJ said in Hume Steel 75 CLR 242 at 252 in respect of the Workers' Compensation Act 1926 (NSW), "[t]here is a distinction, according to the common use of language, between getting hurt and becoming sick. The former would be described as an injury and the latter would generally not be so described". Reference to the authorities shows, however, that there is a long history of judicial consideration of what is meant by "disease" and "injury" in legislation like the SRC Act: see, e.g., May v Military Rehabilitation and Compensation Commission [2015] FCAFC 93; 233 FCR 397 (May v Compensation Commission (FCAFC) at [22]-[120]. 61 Latham CJ's distinction may be accepted, although a problem of categorisation rarely ends here. In Zickar 187 CLR 310 at 332, Toohey, McHugh and Gummow JJ referred to Latham CJ's statement with approval, in considering whether a rupture that led to the worker's brain damage was an injury or a disease in the nature of an aneurism from which he had suffered for some time. As, however, their Honours said (at 334-335), whether it was classified as a disease or not is "related to the circumstances of the case" and, in particular, whether or not the rupture was a result solely of the natural progression of the pre-existing morbid condition, citing Accident Compensation Commission v McIntosh [1991] 2 VR 253 (McIntosh) at 262. In Zickar, their Honours, and Kirby J in a separate judgment, held that the brain damage was the result of an injury, the rupture being distinct from the pre-existing morbid condition. Their Honours in Zickar thus "distinguished between the natural progression of a pre-existing morbid condition or autogenous disease and claims arising from injuries being identifiable 'events' (at 344) such as the rupture of an aneurism or of an oesophagus, or the breaking of an artery": see May v Compensation Commission (FCAFC) at [85]. 62 Several years after Zickar, the High Court in Kennedy Cleaning 200 CLR 286 again considered the distinction between a "disease" and an "injury". In relation to this consideration, the Full Court in May v Compensation Commission (FCAFC) at [105] said: In Kennedy Cleaning, the worker collapsed at work on the occurrence of a brain lesion which caused a stroke, having suffered for some years from rheumatic mitral valve disease. As in Zickar, there was no dispute that her employment did not cause or contribute to the contraction of the disease, or aggravate or accelerate the underlying condition. All members of the Court, except Callinan J, held that the lesion was a "physical injury" within the meaning of s 7(1) of the Workers Compensation Act 1951 (ACT). The majority rejected the argument that the different legislation should lead to a different outcome to that taken by the majority in Zickar, rejecting the submission that the legislative scheme established mutually exclusive classifications of "injury" and "disease". 63 In Kennedy Cleaning Gleeson CJ and Kirby J referred to Zickar and observed (at [35]) that "a long line of decisions ... had recognised that an 'injury', being a sudden or identifiable physiological change, could nonetheless qualify within the ordinary application of that expression ... although the change was internal to the body of the worker". Relevantly for this case, they added (at [35]-[36]): [T]he inclusion in the definition of 'injury' in s 6(1) of the Act of 'mental injury' makes it plain beyond argument in this case that the injuries for which the Act provides are not confined to those originating externally to the body of the worker. Secondly, the mere fact that a sudden physiological change is in some way connected with an underlying 'disease' process does not, of itself, prevent the classification of such a change as an 'injury' within the primary statutory provisions that apply to such a case. 64 With respect to Zickar, McIntosh and Burch, their Honours said (at [39]): All of those cases require that consideration be given to the precise evidence, on a fact by fact basis, concerning the nature and incidents of the physiological change accepted at trial. If this evidence amounts, relevantly, to something that can be described as a sudden and ascertainable or dramatic physiological change or disturbance of the normal physiological state, it may qualify for characterisation as an 'injury' in the primary sense of that word. ... If the propounded 'injury' is distinct from the underlying pathology that constitutes a 'disease' that directly or indirectly caused the sudden event to occur, it is unnecessary to proceed to the alternative and additional basis whereby, in such cases, compensation may also be recovered for the disease process if the statutory preconditions are met. (Citations omitted.) 65 Gaudron J said at [50]: Whether physiological change resulting from a progressive disease that is not employment related is or is not an injury for the purposes of workers' compensation legislation depends on the terms of the legislation in question. There is no doubt that, as a matter of ordinary language, the word 'injury' is apt to include sudden physiological change resulting from a disease, as in the case of stroke resulting from progressive heart disease or the rupture of an aneurysm as a result of the progressive weakening of an arterial wall. (Citation omitted.) 66 McHugh, Gummow and Hayne JJ also said (at [68]) "[t]he circumstance that a sudden physiological change has been caused or provoked by disease does not prevent it from constituting a 'physical injury'" for the purposes of the relevant legislation. 67 More recently, the significance of "suddenness" in characterising an event as an "injury" was explored by the Full Court in May v Compensation Commission (FCAFC) and, on appeal, by the High Court. In May v Compensation Commission (FCAFC) the Full Court said (at [109]-[112]): Adjectives such as "sudden" and "identifiable" help emphasise the distinction made in both Zickar (by the majority) and Kennedy Cleaning between a disease and some of its consequences or effects; they also reflect the historical fact that injuries often occurred in the workplace in the context of an "accident". We do not, however, see in the statutory concept of injury in the SRC Act any necessity for the attribute of "suddenness". The passage from the judgment of Latham CJ in Hume Steel at 252-253 has force, not as a substitute definition, but as an informing guide to the content or meaning of the word, including its relationship to ordinary meaning or common understanding. ... In circumstances where one has physiological change, and the enquiry is whether there is the mere progression of a disease, or an event or identifiable change that can be seen as a separate injury, there will be room for debate and factual assessment. Suddenness may assist in the demarcation of the injury from the progression of the disease. (Emphasis in original.) 68 In Compensation Commission v May in the High Court, the plurality agreed (at [47]) that "suddenness" was not necessary for there to be an injury "in the primary sense". The plurality added, however: A physiological change might be "sudden and ascertainable". A physiological change might be "dramatic". The employee's condition might be a "disturbance of the normal physiological state". That an "injury" in the primary sense can arise, and can be described, in a variety of ways does not mean that "suddenness" is irrelevant. As the Full Court said, "suddenness" is often useful where there is a need to distinguish a physiological change from the natural progress of an underlying (and in one sense, closely related) disease (as occurred in [Zickar] and Kennedy Cleaning). But it is the physiological change - the nature and incidents of that change - that remains central. (Citations omitted; emphasis in original.) 69 Agreeing in the result, Gageler J said (at [75]): An injury, it has long been repeatedly explained, is some definite or distinct "physiological change" or "physiological disturbance" for the worse which, if not "sudden", is at least "identifiable". 70 The plurality emphasised (at [49]) that the SRC Act required the Tribunal as the finder of fact to consider the evidence that it accepted and to address the following questions (at [50]-[54]) in order to determine whether the employee was suffering from a "disease" or "injury (other than a disease)". First, does the evidence amount, relevantly, to something that can be described as an "ailment", being a physical or mental ailment, disorder, defect or morbid condition? Second, if so, was that state contributed to in a material degree by the employee's employment by the Commonwealth? If the answer to both those questions is "Yes", there is a 'disease' within para (a) of the definition of "injury". Of course, in some cases, the answer to those questions may be admitted. That is, the employee may admit that the answer to the first question, or both the first and the second questions, is "No". If there is not a "disease" within para (a) of the definition of "injury", the tribunal of fact next inquires whether there is an "injury (other than a disease)" within para (b). The third question is - does the evidence demonstrate the existence of a physical or mental "injury" (in the primary sense of that word)? Generally, that will be determined by asking whether the employee has suffered something that can be described as a sudden and ascertainable or dramatic physiological change or disturbance of the normal physiological state. However, that judicial language is not to be construed or applied as if it were the words of a statute defining a necessary condition for the existence of an "injury (other than a disease)". The language of judgments should not "be applied literally to facts without further consideration of what is conveyed by the reasoning" in the cases from which it is derived, or without regard to the text and scheme of the Act. If there be an "injury" in the primary sense of the word, the next question is - did that injury arise out of, or in the course of, the employee's employment by the Commonwealth? If that question is answered "Yes", there is an "injury (other than a disease)" within para (b) of the definition of "injury" in s 4(1) of the Act. In some circumstances, if the answer is "No", it may be necessary to ask whether the case is one involving aggravation of an injury. That question does not arise in this appeal. It may be that there are circumstances in which the identification of a physiological change, a disturbance of the normal physiological state or a psychiatric disorder may satisfy the definition of "ailment" (and therefore result in a positive answer to the first question) but the second question is answered "No". But if that is the position on the evidence, there will not be any relevant overlap between a "disease" and an "injury (other than a disease)" in the definition of "injury" in s 4(1) of the Act. It reflects the fact that there are marked differences between arising "out of" or "in the course of" (in para (b)) and "contributed to in a material degree" (for para (a)) in the definition of "injury". And it simply means that the employee was unable to satisfy the different level of employment connection required under para (a) of the definition of "injury" under the Act. (Citations omitted; emphasis added.) 71 As we have seen, in support of her first and second grounds, Mrs Prain's contention was that, having regard to the authorities, "suddenness" was not a "touchstone" for "injury"; and that the Tribunal erred in holding at [20] of its reasons that, "in emphasising the continued utility of sudden or identifiable physiological change in the normal functioning of the body as the touchstone for injury", the High Court in Compensation Commission v May affirmed "the long line of authorities which have tended to place mental illness in the statutory category of disease". As noted already, Mrs Prain submitted that this error was continued at [42] of the Tribunal's reasons, where it said that Compensation Commission v May "affirmed the continuing relevance of the test ...: a sudden and ascertainable or dramatic physiological change or disturbance of the normal physiological state" and held that there was no single, definable moment or moments from 11 to 19 April 2011 when she "might be said to have sustained a change or disturbance ... amounting to a psychological injury". Mrs Prain also submitted that there were other features of the Tribunal's reasons that showed that the Tribunal proceeded on the erroneous basis that a mental illness was to be categorised as a "disease" and that such an illness could not be "injury (other than a disease)". These other features were: the heading above [13] ("Is Mrs Prain's psychiatric condition an injury or a disease") read with [13] itself; and the reference to Comcare v Mooi 69 FCR 439, at [15] and [20] of the Tribunal's reasons. 72 The authorities to which we have already referred show that if the Tribunal did in fact treat "disease" and "injury (other than disease)" as mutually exclusive categories, it would have been in error. We are not, however, persuaded that it did so. A fair reading of the Tribunal's reasons indicates that the Tribunal did in fact address the question whether Mrs Prain's adjustment reaction was "an injury (other than a disease)" and determined that it was not. Further, we are satisfied that the Tribunal asked itself the correct statutory questions and that the conclusions it reached on these questions were open to it. 73 Reference to [13]-[15] of the Tribunal's reasons shows that, in those paragraphs, the Tribunal set forth the opposing arguments and clearly recognised that the argument for Mrs Prain included her submission that "an adjustment disorder ... is the paradigm case of a mental injury and not a disease". It may reasonably be inferred that the Tribunal had this submission in mind in the reasons that followed. Further, reference to [18] of the Tribunal's reasons makes plain that the Tribunal was aware of what the High Court in Compensation Commission v May had said about the significance of "suddenness", specifically setting out the relevant passage in the plurality's reasons in that case: see [68] above. Read in this way, we can discern no relevant error in [20] of the Tribunal's reasons. We understand the Tribunal was acknowledging in this paragraph that suddenness is "often useful", particularly in distinguishing physiological change from the natural progression of a disease, although suddenness is not a prerequisite to a finding of "injury". There was no error in it so doing. Compensation Commission v May shows that the quality of "suddenness" is not necessarily irrelevant; and whether or not it is significant in a particular case depends on what the particular facts and circumstances show about the nature and incidents of physiological or psychological change. 74 Further, we do not consider that the reference at [20] of the Tribunal's reasons to Comcare v Mooi was misplaced. We do not think that it was impermissible for the Tribunal to note that the authorities "tended to place mental illness in the statutory category of disease". We would not read the Tribunal's statements in [20] of its reasons as requiring the conclusion that mental illness must be categorised as a disease and, for that reason, could not also be classed as an "injury (other than a disease)". Once again the Tribunal's reasons assumed, correctly, that whether or not a mental illness is to be categorised as a "disease" or, alternatively, an "injury (other than a disease)" will depend on the nature and incidents of the psychological change. 75 On one view, [21] and [42] of the Tribunal's reasons fit together inelegantly, since, in [21], the Tribunal records its finding that "Mrs Prain suffered a disease arising from her employment at the Canberra Hospital" and, in the subsequent [42], reiterates its finding that she suffered a "disease" arising from incidents there. On a fair reading of the Tribunal's reasons, however, the paragraphs do not support the attribution of any relevant error. Paragraph [21] is expressed as referable to the principles that the Tribunal has discussed and to "the reasons set out below"; and [21] and [42] are not inconsistent with one another. The intervening paragraphs indicate that the Tribunal examined in detail the nature and incidents of the psychological change suffered by Mrs Prain, as the High Court in Compensation Commission v May required. This much appears from its analysis of the evidence of Mrs Prain and of her husband who gave oral evidence to the Tribunal, as well as the evidence of family and friends whose statements were tendered. It also appears from the analysis of the medical and psychological evidence before the Tribunal. When considered in light of these analyses, [42] of the Tribunal's reasons is unobjectionable. Rather, it demonstrates that the Tribunal considered the nature and incidents of Mrs Prain's condition to form the opinion that she suffered something that could be described as an "ailment", being a physical or mental ailment, disorder, defect or morbid condition; and that could not be described as a physical or mental "injury" (in the primary sense of the word injury). 76 In reaching this latter conclusion, the Tribunal evidently had regard to "suddenness" or the existence of "dramatic" change and, in this context, found that her psychological condition was "the outcome of a slow build-up of hurt and resentment rather than of a climatic episode", being a circumstance that, in its opinion as expressed at [42], supported a finding of disease and not a finding of injury in the primary sense. This approach was, we have seen, consistent with Compensation Commission v May (see [68]-[70] above). It was evidently open to the Tribunal on the evidence before it to reach this conclusion. The use of the words "touchstone" in [20] and "test" in [42] are inapt descriptions of the significance of "suddenness" and like factors in determining the existence of an "injury (other than a disease)". On a fair reading of the Tribunal's reasons (cf Minister for Immigration and Ethnic Affairs v Wu Shan Liang [1996] HCA 6; 185 CLR 259 at 272), however, we would not understand the Tribunal's use of these words to indicate that it was treating suddenness, dramatic change or the like as a necessary condition for a finding of "injury (other than disease)". Nor do we consider the fact that the Tribunal did not expressly find that there was no mental injury in the primary sense indicates that the Tribunal regarded the categories of "disease" and "injury (other than disease)" (being injury in the primary sense) as mutually exclusive. Rather, we would infer from the Tribunal's reasons that it rejected Mrs Prain's case that she suffered from a (mental) injury simpliciter or in the primary sense. Amongst other things, the Tribunal's previous statement of the parties' arguments and discussion of Compensation Commission v May at [18]-[19] of its reasons and its reference in this context to the utility or relevance of suddenness and like factors, as well as its analysis of the evidence and its findings in [42], is indicative of a correct approach. This was a case in which the Tribunal examined the evidence before it in order to determine the nature and incidents of the change to Mrs Prain's mental state, as the authorities required: see Compensation Commission v May at [62]. 77 The Tribunal found that Mrs Prain lost her equilibrium at some point between 11 and 19 April 2011 (see [42]). The Tribunal's reasons (at [26]) also indicate that there was evidence that she was suffering from various symptoms shortly after her employment ended. As the plurality's reasons for judgment emphasise in Compensation Commission v May at [61], more is needed to justify a finding of injury, including mental injury, than evidence that the employee was experiencing certain symptoms of being unwell: see also [77] (Gageler J). It is relevant, in this context, also to bear in mind the statement of the plurality (at [52]) that "the existence of a physical or mental 'injury' (in the primary sense of that word)" will generally "be determined by asking whether the employee has suffered something that can be described as a sudden and ascertainable or dramatic physiological or disturbance of the normal physiological state" (or a psychiatric disorder, see n 65): see also Compensation Commission v May at [62]. The Tribunal's finding (at [42] of its reasons) that Mrs Prain's "loss of equilibrium seemed to be the outcome of a slow build-up of hurt and resentment rather than of a climactic episode of confrontation or conflict" was consistent with this approach; and, having regard to Compensation Commission v May, on the facts as found by the Tribunal, it was clearly open to it to reject Mrs Prain's claim that she suffered an injury in the primary sense. 78 For the reasons stated, we do not consider that grounds 1 and 2 are made out. It seems to us that the Tribunal understood and addressed the correct statutory questions.

Ground 3 79 By ground 3, Mrs Prain claimed that the Tribunal had "misapplied s 5B of the [SRC Act] in holding that the 'employment factor' had 'ceased to be a significant contributor to [her] adjustment disorder by July 2015' on the basis that each ('or at least most') of the other factors to which it referred was a novus actus interveniens". 80 As we have seen, the Tribunal found that the condition suffered by Mrs Prain arising from her employment at the Canberra Hospital was a disease and, applying the test in s 5B of the SRC Act, her employment contributed to a significant degree to the ailment she suffered at that time. As already noted, Comcare's case that unfortunate events in Mrs Prain's life had "crowded out what occurred at the Canberra Hospital as the major contributors" to her mental ill-health since April 2011 was met by Mrs Prain with the proposition that those subsequent events were simply "manifestations" of the condition she suffered in April 2011. Mrs Prain submitted to the Tribunal that the events at the Canberra Hospital "may not have been the proximate cause of any adjustment disorder experienced by [her] in 2015, but ... there was an unbroken chain of causation linking the more recent factors with those work-related incidents: see Tribunal's reasons at [44] (emphasis in original). As the Tribunal's reasons show, the Tribunal sought to address the parties' competing submissions by a careful evaluation of the evidence, noting at the outset (at [45]) that "there was a body of evidence ... supporting each hypothesis". 81 In considering Mrs Prain's evidence, the Tribunal observed (at [50]) that her evidence gave rise to "more than a few incongruities and contradictions", which it considered were "symptomatic of [her] quite relentless focus ... on tying all her current physical and mental problems to the incidents at Canberra Hospital". In an adverse credit finding, the Tribunal found (at [51]) that "[t]his relentless attribution [was] rehearsed and self-serving"; and that this appraisal was "reinforced by somewhat unconvincing attempts to wave aside evidence inconsistent with this thesis" and "involved discounting the impact of any issue in her life, other than the Canberra Hospital issue, which might have contributed to her unhappiness". It was in this context that the Tribunal concluded (at [59]) that Mrs Prain had exaggerated her claims, and that "other setbacks in her life had a greater impact on her mental well-being than she was prepared to concede". The Tribunal did not for this reason alone reject her claim that her employment at the Canberra Hospital continued to contribute to a significant degree to the ailment from which she suffered. 82 In assessing Mrs Prain's submissions in this regard, the Tribunal also directed its attention to matters that, under s 5B(2), the Tribunal could take into account in determining whether the relevant employment had contributed to a significant degree to an employee's ailment. There was no error in the Tribunal taking into account the duration of Mrs Prain's employment at the Canberra Hospital or her predisposition to the ailment, since this was expressly permitted by that provision. Nor do we discern any relevant error in the Tribunal's conclusion (at [66]) that "the effect of the relevant factors in s 5B(2) must be to diminish to some degree the weight attached in this case to the Canberra Hospital issues vis-à-vis other issues contributing to her mental disorder". This conclusion was open to the Tribunal, having regard to s 5B(2) and the evidence before it. 83 Senior Counsel for Mrs Prain contended that the Tribunal "look[ed] for different factors and ... weigh[ed] them", rather than considering the contribution and significance of those factors. The Tribunal's discussion of matters mentioned in s 5B(2) indicates, however, that the task it undertook was the very one that Mr Kennett SC advocated. That is, the Tribunal sought to evaluate the effect of these matters on the contribution of the relevant employment to the employee's ailment, and the significance of that contribution. As we have said, we do not consider that the Tribunal's consideration of relevant matters listed in s 5B(2) led it into material error. 84 Given the case Mrs Prain sought to make, the Tribunal's appraisal of her evidence and the s 5B(2) matters, the evidence of her state of mind as reported by her psychologist, Mr Lurie, was important. In this context, the Tribunal stated (at [68]) that it was driven by the relevant evidence "towards the conclusion that the prominence of the employment issues in her mind had withered as other issues had taken their place". The Tribunal said (at [68]-[69]): Those [employment] issues may well have been, as Mr Lurie suggested, the trigger for some of Mrs Prain's later worries, but given her marked susceptibility to stresses of any kind it seems improbable that one particular stressor - the week-long conflict at the hospital four years previously - should still amount to a significant factor in her ongoing condition. The alternative view, put by Mr Anforth, was that many of the later stressors were linked to the April 2011 injury, and that they would simply not have occurred but for the disrupted personality, the damage to her self-perception and value system occasioned by her employment. The Tribunal accepts that there may be a causal linkage, but would have been more inclined to anchor the later events with employment if a more persuasive narrative of that had been evident. As it was, the linkage was postulated almost entirely through the evidence of Mrs Prain's perceptions of what was destabilising her mind and, as already indicated, the Tribunal lacks confidence in that evidence without corroboration. (Emphasis added.) 85 The Tribunal's conclusion at [70], which is the focus of attack in ground 3, read as follows: The better view is that each - or at least most - of the factors which the medical records suggest were agitating Mrs Prain after April 2011 was a novus actus interveniens, having the effect of pushing the employment factor further and further into the background. Taking the evidence as a whole, the Tribunal regards that factor as having ceased to be a significant contributor to Mrs Prain's adjustment disorder by July 2015. The respondent here has met its responsibility (as set out in [Comcare v ] Power [[2015] FCA 1502; 238 FCR 187]) to demonstrate what other factors are likely to have accounted for her ongoing psychological symptoms after 16 July 2015. Accordingly, the Tribunal affirms the reviewable decision of 13 August 2015. We accept that the Tribunal was not using the expression "novus actus interveniens" in any technical sense, and that its use of the expression was intended only to signify that, as it said, other factors after April 2011 arose and pushed the employment factor "into the background". 86 We reject Mrs Prain's contention in support of ground 3, that the Tribunal failed to address the case that she put or the statutory test in s 5B(1) of the SRC Act. As we have seen, the Tribunal specifically set out the parties' opposing contentions and addressed Mrs Prain's case in its analysis, first, of Mrs Prain's own evidence and, then, through a discussion of the psychological and medical evidence concerning her mental state. 87 Further, reading the Tribunal's reasons as a whole, we are not persuaded that the Tribunal failed to address the test in s 5B(1) of the SRC Act. Its appraisals of the evidence and relevant determinations show that it understood and applied itself to the statutory question to which s 5B(1) gave rise, namely, whether Mrs Prain's ailment was contributed to, to a significant degree, by her employment at the Canberra Hospital. The Tribunal specifically acknowledged (at [60]) that, notwithstanding its doubts about some of her evidence, Mrs Prain was "entitled to succeed if the compensable factors have nonetheless contributed to that injury to a significant degree". Whilst its reference to "compensable factors" (as was its reference to "novus actus interveniens" in [70]) were inapt, reading the Tribunal's reasons as a whole, it is clear that the Tribunal had in mind the contribution made by Mrs Prain's employment at the Canberra Hospital to her condition after July 2015 and that its reference to "factors" was to this issue and to the factors listed in s 5B(2) that might, in the Tribunal's discretion, be considered in determining the question to which s 5B(1) gave rise and to which the Tribunal directed its attention at [65] and following. The Tribunal's statement (at [68]) that "it seems improbable that one particular stressor - the week-long conflict at the hospital four years previously - should still amount to a significant factor in her ongoing condition" should be understood as the application of that test. It is in this context that one must understand and read the Tribunal's further statements (at [70]) that "the factors which the medical records suggest were agitating Mrs Prain after April 2011" had "the effect of pushing the employment factor further and further into the background". Taking the evidence as a whole, it is plain enough that the Tribunal's determination (at [70]) that Mrs Prain's employment at the Canberra Hospital had ceased to be "a significant contributor to Mrs Prain's adjustment disorder by July 2015" was reached after considering the case Mrs Prain sought to make and correctly addressing the question to which s 5B gave rise. The Tribunal's reasoning at this point is also consistent with its appreciation that, under s 5B(3), "significant degree" meant "substantially more than material". Accordingly, we consider that ground 3 is not made out.

Section 19 88 We note that counsel for both parties raised the possibility that the Tribunal failed to address s 19 of the SRC Act, but both were content to treat the test in s 5B as the one on which Mrs Prain's claim ultimately depended. We do not think that there is any error arising from the Tribunal's treatment of s 19. 89 The Tribunal concluded (at [71]) that Comcare was not liable for a compensable condition under s 14 of the SRC Act. It was therefore unnecessary for the Tribunal to consider s 19 (or s 16) which were the provisions under which Comcare determined that Mrs Prain had no entitlement to compensation: see Telstra Corporation Ltd v Hannaford [2006] FCAFC 87; 151 FCR 253 at [57]-[59]. This is because s 14 creates a liability to pay compensation "in accordance with" the SRC Act, that is, a liability to pay the compensation for which provision is made in sections such as ss 16 and 19. As stated by the Full Court in Lees v Comcare [1999] FCA 753; 29 AAR 350 at [27]: [Section] 14 is the central provision of the Act so far as the liability of Comcare to pay compensation is concerned. Section 14 creates a liability in Comcare in respect of injuries suffered by employees which result in death, incapacity for work or impairment. However, the liability in Comcare created by s 14 is qualified in two ways. First, such liability is a liability "[s]ubject to" Part II of the Act. That is, it is a liability limited in its extent by other provisions of Part II of the Act (see, for example, s 17(2)). Secondly, the liability is a liability to pay compensation "in accordance with" the Act. That is, it is a liability to pay the compensation for which the statute provides, as required by the Act (see, for example, ss 17(3)(4) and (5), 19, 20, 24 and 25). 90 The parties did not invite the Tribunal to take any different approach. We accept that, as counsel for Comcare submitted, in considering how the Tribunal approached its task, it is also relevant to consider the way in which the parties ran their respective cases before the Tribunal. In this case, having regard to the way Mrs Prain ran her case, as Comcare submitted, it came down to "whether the ongoing adjustment disorder after 16 July 2015 [was] a continuation of the adjustment disorder before that date". The Tribunal's reasons reflect the fact that this was indeed the case that Mrs Prain made before the Tribunal and that it was this case that the Tribunal specifically addressed and rejected at [68] to [70] of its reasons.

Disposition 91 For the foregoing reasons, we would dismiss, with costs, Mrs Prain's appeal under s 44 of the AAT Act. I certify that the preceding ninety-one (91) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justices Kenny, Tracey and Bromberg .