Statement of Principles concerning chronic multisymptom illness (Reasonable Hypothesis) (No. 3 of 2020)

The central concept is “chronic multisymptom illness” as defined in subsection 7(2). The definition has three cumulative requirements. First, there must be one or more current symptoms from at least two of three specified categories: (i) fatigue; (ii) mood-cognition (feeling depressed, difficulty remembering or concentrating, feeling moody, feeling anxious, trouble finding words or difficulty sleeping); (iii) musculoskeletal (joint pain, joint stiffness or muscle pain). The symptoms must be current at the time of diagnosis, not merely historical. Second, the collection of symptoms relied upon must be distressing and result in significant disruption of social and occupational functioning. This is a functional impairment threshold; trivial or mild symptoms will not qualify. Third, the symptom collection must have persisted for at least six consecutive months. The diagnosis must be made by a specialist physician or a psychiatrist, which excludes general practitioners, physiotherapists, psychologists or other allied health professionals. The SoP does not require a particular aetiology or a label such as “chronic fatigue syndrome” or “fibromyalgia”; it uses a symptom-based case definition that is agnostic as to underlying cause.

The next concept is the distinction between category 1A and category 1B stressors, both defined in the dictionary. A category 1A stressor involves a direct severe traumatic event experienced by the person: a life-threatening event; serious physical attack or assault including rape and sexual molestation; or being threatened with a weapon, held captive, kidnapped or tortured. A category 1B stressor involves events where the person is a participant or eyewitness: killing or maiming a person; being an eyewitness to a person being killed or critically injured; being an eyewitness to atrocities inflicted on another person; participating in the clearance of a corpse or critically injured casualty; or viewing a corpse or critically injured casualty as an eyewitness. The dictionary further defines “corpse” as human remains or body parts of one or more persons who have met a violent or horrific death, with examples including death due to suicide, gunshot, improvised explosive devices, natural and technological disasters, terrorist attacks or motor vehicle accidents. Seeing a closed body bag or viewing a body in an open-casket coffin is excluded. “Eyewitness” requires first-hand experience; exposure only to public broadcasting or mass media coverage is insufficient.

“Hostile or life-threatening environment” is defined by example: experiencing or being under threat of artillery, missile, rocket, mine or bomb attack; experiencing or being under threat of nuclear, biological or chemical agent attack; or being involved in combat or going on combat patrols. This is a narrow definition limited to combat or combat-like settings; it does not include, for example, serving in a dangerous peacekeeping zone without actual combat patrols or threat of attack.

The concept of “relevant service” is defined in the dictionary and includes operational service, peacekeeping service, hazardous service, British nuclear test defence service under the VEA, and warlike or non-warlike service under the MRCA. The SoP therefore covers the full range of accruing service types but excludes peacetime or non-operational service that does not fall within those categories.

Finally, the SoP operates on a “reasonable hypothesis” standard, meaning the claimant does not need to prove causation on the balance of probabilities; a hypothesis that is plausible and consistent with the medical-scientific evidence will suffice, provided it is not contrary to proven facts or impossible. The basis for determining the factors is set out in section 8: the Repatriation Medical Authority is of the view that there is sound medical-scientific evidence that indicates that CMI and death from CMI can be related to relevant service. The instrument does not specify what that evidence is, but the Authority’s view is effectively delegated legislative fact-finding.

The SoP directly affects three groups: veterans and serving members with relevant service; the decision-makers in the Department of Veterans’ Affairs and the Veterans’ Review Board and the Administrative Appeals Tribunal; and the medical specialists who must diagnose the condition. For veterans and members, the SoP determines whether a claim for CMI will succeed or fail at the reasonable hypothesis stage. A veteran who cannot obtain a diagnosis from a specialist physician or psychiatrist will be unable to raise a reasonable hypothesis, regardless of symptoms. A veteran whose symptoms do not meet the three-category, six-month, significant disruption criteria likewise cannot succeed. The instrument therefore imposes a gatekeeping function that restricts compensation to a defined clinical picture. It affects especially veterans with service in combat zones, peacekeeping missions, hazardous service or British nuclear test defence service, as these are the service types that give rise to relevant service. The instrument also matters for families claiming death from CMI; they must show that the proximate cause of death (pneumonia, respiratory failure, cardiac arrest, circulatory failure or cessation of brain function) was contributed to by the person’s CMI (subsection 7(3)).

For decision-makers, the SoP is binding. Under section 120A of the VEA and section 338 of the MRCA, a decision-maker must apply the relevant SoP when determining whether a reasonable hypothesis exists. The SoP replaces the earlier 2014 SoP for all claims made on or after 23 March 2020, and applies to claims made before that date if the decision has not been finally determined (section 5). Decision-makers must navigate the definitions carefully: they cannot accept a diagnosis from a general practitioner; they must determine whether the person experienced a category 1A or 1B stressor within the six-month window before clinical onset; they must assess whether the person lived or worked in a hostile or life-threatening environment for at least 28 days; and they must ensure that the factor is related to the person’s relevant service (section 10(1)). The inability to obtain appropriate clinical management factor (section 9(4)) is narrower: it applies only to material contribution to or aggravation of CMI that existed before or during (but did not arise out of) the person’s relevant service. This distinction matters for claims where the person already had CMI before service and the service made it worse.

For medical specialists, the SoP creates a de facto standard for diagnosis in the veterans’ compensation system. A diagnosis of CMI for compensation purposes must align with the SoP’s definition. A specialist who diagnoses CMI using a different classification system (such as the DSM-5 somatic symptom disorder or the CDC criteria for chronic fatigue syndrome) should be aware that the SoP uses its own unique symptom categories and functional impairment threshold. Specialists may be required to provide reports that specifically address whether the symptom collection is distressing and results in significant disruption of social and occupational functioning, and whether the symptoms have persisted for six consecutive months.

The SoP itself does not impose duties or confer rights directly on individuals; it is a legislative instrument that structures the duties of decision-makers and the rights of claimants within the existing framework of the VEA and MRCA. The primary right that the SoP engages is a claimant’s right to have a reasonable hypothesis accepted if at least one factor exists and is related to service. This right is not absolute: the decision-maker must still be satisfied that the hypothesis is not disproved beyond reasonable doubt, and the SoP only lists factors that “must exist” as a minimum. A claimant who satisfies, for example, that they experienced a category 1A stressor within six months before clinical onset of CMI has raised a factor; the decision-maker must then consider whether there is any contrary evidence that disproves the hypothesis. The burden of proof on the decision-maker is to disprove the hypothesis beyond reasonable doubt, not to prove it.

The corresponding duty on the decision-maker is to apply the SoP as in force at the time of determination. The instrument is not discretionary; a decision-maker cannot accept a diagnosis that does not meet the definition, even if other medical opinion supports it. The duty includes properly construing the definitions: for example, “hostile or life-threatening environment” is limited to the three examples in the dictionary, and “eyewitness” excludes media exposure. A decision-maker who misapplies the definition can be reversed on review.

There is no private right of action under this SoP; enforcement occurs through the internal review and tribunal processes. Claimants have the right to seek review of an adverse decision by the Veterans’ Review Board and then the Administrative Appeals Tribunal. The tribunal must itself apply the SoP, but it may give weight to different medical evidence. The SoP also does not create any duty on veterans to seek appropriate clinical management; the factor in section 9(4) is framed as a causal factor that can be relied upon, not a duty. However, if a veteran fails to obtain appropriate clinical management for CMI, that factor might be available to raise a hypothesis, but only for aggravation of a pre-existing condition.

For medical specialists, there is no duty to diagnose CMI in accordance with the SoP; the instrument only determines what evidence will be accepted by the decision-maker. A specialist may diagnose CMI using other criteria; if the diagnosis does not match the SoP’s definition, the claimant may need to seek a different specialist or argue that the diagnosis substantially meets the definition. The instrument also does not create a right to be examined by a specialist; claimants must arrange their own medical evidence.

The SoP contains no penalty provisions. Enforcement of the instrument occurs through the claims adjudication process rather than through any punitive mechanism. If a claimant fails to raise a reasonable hypothesis because they cannot satisfy a factor or the diagnostic definition, the claim is rejected. Rejection is not a penalty; it is an administrative outcome. The only enforcement mechanism is the possibility of an adverse inference if a claimant misrepresents symptoms or service history, but that is governed by general criminal law provisions in the Criminal Code and the VEA, not by this SoP.

The SoP does, however, have a serious practical effect on entitlement. A veteran who could have succeeded under the 2014 SoP may now fail if they cannot meet the new, more restrictive definition. That is not a penalty but a change in eligibility standards. The instrument’s repeal clause means that the 2014 SoP no longer applies to claims made on or after 23 March 2020. There is no transitional penalty for failing to comply with the new SoP; it simply replaces the old one.

For decision-makers who apply the SoP incorrectly, the enforcement mechanism is judicial review. A decision that fails to apply the correct SoP or misconstrues its terms is reviewable under the Administrative Decisions (Judicial Review) Act 1977. The tribunal can also set aside a decision and substitute its own. But the SoP itself does not create penalties for erroneous decisions; the remedies are reversal and remittal.

The fundamental enforcement lever is the refusal of the claim. That refusal may have downstream consequences: a veteran who is denied CMI compensation may also be denied access to related benefits such as incapacity payments, medical treatment under the MRCA, or the Gold Card under the VEA. The SoP thus indirectly controls access to a range of entitlements, but it does so through the causal link requirement, not through direct penalties.

This SoP is made under subsection 196B(2) of the VEA and applies to claims to which section 120A of the VEA or section 338 of the MRCA applies. Section 120A of the VEA provides that the standard of proof for claims relating to operational service is reasonable hypothesis, and that a hypothesis cannot be reasonable unless it is consistent with the template in a relevant SoP. Section 338 of the MRCA is the equivalent provision. The SoP is therefore the authoritative template for all CMI claims under both Acts. It overrides any inconsistent medical opinions or common-law principles of causation. A decision-maker cannot find a reasonable hypothesis based on evidence that is inconsistent with the SoP’s factors.

The SoP also interacts with other SoPs through section 11. If a factor in section 9 refers to an injury or disease covered by another SoP (for example, if the factor is experiencing a category 1A stressor and that stressor causes a separate injury), then the factors in that other SoP apply. This creates a layered causation analysis: the decision-maker may need to refer to the SoP for post-traumatic stress disorder or for another relevant condition to determine whether the factor itself is service-related. Section 11 ensures that the SoP does not need to replicate the entire matrix of service-related illnesses.

The instrument expressly repeals the Statement of Principles concerning chronic multisymptom illness No. 55 of 2014. The 2014 SoP was made under both subsections 196B(2) and (8) of the VEA. Subsection 196B(8) provides for SoPs dealing with the standard of reasonable satisfaction (balance of probabilities). This new SoP is only under subsection (2) and is therefore limited to the reasonable hypothesis standard. This change is significant: the 2014 SoP could be used for both types of claims, but the 2020 SoP applies only to claims where the standard is reasonable hypothesis. Claims requiring proof on the balance of probabilities (for example, claims under the VEA for incapacities from non-operational service where the standard is reasonable satisfaction) would not be governed by this SoP. Those claimants might need to rely on other pathogenesis theories, or the decision-maker might still apply the SoP factors as relevant medical evidence but not as a binding template. The application section (section 5) limits the instrument to claims under section 120A VEA or section 338 MRCA, which are the provisions for the reasonable hypothesis standard. This is a crucial interaction point that practitioners must note.

The SoP interacts with the Veterans’ Entitlements Act itself concerning the definition of “relevant service”. It does not alter the VEA definitions; it incorporates them by reference. The dictionary defines “relevant service” by listing six categories from the VEA and MRCA. This means that a person with peacetime service only (non-operational service under the VEA that is not hazardous, British nuclear test defence, peacekeeping or operational) cannot raise a claim under this SoP because they lack relevant service. Similarly, a member of the Australian Defence Force who served only in a non-warlike, non-hazardous capacity may not have relevant service for CMI.

The SoP does not interact with state workers’ compensation schemes, motor vehicle accident schemes, or private disability insurance. It is confined to the Commonwealth military compensation system. However, a veteran who also has a private income protection policy might find that the insurer uses different diagnostic criteria, potentially leading to inconsistent outcomes.

The instrument itself notes that it repeals the Statement of Principles concerning chronic multisymptom illness No. 55 of 2014 (Federal Register of Legislation No. F2014L00524). The 2014 SoP was determined following an investigation concerning Gulf War syndrome that commenced on 31 October 2012. The note states that although that investigation concerned the health of Gulf War veterans, the new SoP applies to all veterans and serving members with relevant service who have an illness meeting the definition. The 2014 SoP was made under both subsections 196B(2) and (8) of the VEA; this 2020 SoP is made only under subsection (2). This suggests that the Repatriation Medical Authority considered that there is sound medical-scientific evidence for the reasonable hypothesis standard but not necessarily for the reasonable satisfaction standard (or that the Authority decided to issue separate instruments for each standard). Practitioners should verify whether a separate SoP under subsection (8) exists; as of the date of this instrument, none is referenced.

At the time of writing, there is no public amendment history beyond the repeal. The instrument commenced on 23 March 2020 and remains in force unless amended or replaced. The Authority retains power under the VEA to revoke or amend SoPs as new medical evidence emerges. The note to the repeal clause suggests that the 2014 SoP was specifically linked to Gulf War syndrome research, but the 2020 SoP broadens the application to all relevant service, ostensibly reflecting a shift in medical understanding that CMI is not unique to Gulf War veterans. The absence of any transitional provisions means that claims lodged before 23 March 2020 but not yet determined will be decided under the new SoP, unless the claim has already been determined and is final. This is a standard feature of SoPs; they apply to claims not finally determined as of commencement.

The instrument itself does not reference any litigation. However, as a legislative instrument made by the Repatriation Medical Authority, its predecessor SoPs have been the subject of review in the Administrative Appeals Tribunal and the Federal Court. The definition of CMI under the 2014 SoP may have been litigated concerning whether the symptom categories required symptoms from all three categories or only two; the 2020 SoP now expressly requires symptoms from two categories. The meaning of “hostile or life-threatening environment”, “category 1A stressor” and “category 1B stressor” is likely to generate disputes in applications where the veteran’s service involved events that fall close to the boundary - for example, whether being in a combat zone without going on patrols constitutes “being involved in combat” for the purposes of the hostile environment definition. The dictionary definition of “eyewitness” excluding media exposure has been the subject of AAT decisions under other SoPs and may be relevant here.

No specific case names are provided in the instrument, so none will be cited. The practitioner should note that the Federal Court has considered the role of SoPs in general, including the standard of review. The High Court in Repatriation Commission v Hancock (2003) and other cases established that the reasonable hypothesis test does not require medical certainty and that the decision-maker must accept a hypothesis that is plausible and consistent with the SoP factors. However, the court also held that if the hypothesis is inconsistent with the factors, it cannot succeed. This means that a veteran who cannot fit their CMI into the SoP’s definition cannot argue that the SoP is wrong; the SoP is binding as a delegated legislative instrument.

The likelihood of litigation over this SoP is moderate. Claimants who have a diagnosis of fibromyalgia or chronic fatigue syndrome from a general practitioner may attempt to argue that a rheumatologist or infectious disease physician qualifies as a “specialist physician”. That issue may be tested. Similarly, the requirement that symptoms be “current” and that the six-month persistence refers to the “collection of symptoms relied upon” may lead to disputes about the precise time frame.

Several provisions create traps for the unwary. The first is the diagnostic requirement. Only a specialist physician or a psychiatrist can make the diagnosis. A diagnosis from a general practitioner, a rehabilitation physician (if not a specialist physician), a rheumatologist (who is a specialist physician) is acceptable, but the wording “specialist physician” is narrower than “medical specialist”. The dictionary does not define “specialist physician”, but ordinarily it refers to a physician who has completed advanced training in internal medicine and holds Fellowship of the Royal Australasian College of Physicians. A surgeon, anaesthetist or obstetrician is not a specialist physician. Psychiatrists are explicitly included. A diagnosis from a psychologist or a physiotherapist is invalid.

The second trap is the symptom category requirement. The definition requires current symptoms from two of three categories. A veteran who has only fatigue and mood-cognition symptoms but no musculoskeletal symptoms satisfies two categories; but if they have only fatigue and muscle pain (one category from fatigue, one from musculoskeletal) that is also sufficient. However, if they have only fatigue (one category) even if severe, they do not meet the definition. The symptoms must also be “current” at the time of diagnosis. Chronic symptoms that have resolved by the time of assessment may not suffice; the claimant must have ongoing symptoms.

The third trap is the six-month persistence requirement. The definition states that “the collection of symptoms relied upon to make the diagnosis must have persisted for at least six consecutive months”. It does not require that each individual symptom be present for the entire six months, but the pattern of symptoms must have been present for that duration. A veteran who has had fatigue for three months and then developed joint stiffness for the next three months might argue that the collection persisted for six months, but the decision-maker could contend that the symptom set changed. This ambiguity may require expert evidence.

The fourth trap is the timing of the factors. Factor (1) requires living or working in a hostile or life-threatening environment for at least 28 days in the six months before clinical onset. Factor (2) (category 1A stressor) and factor (3) (category 1B stressor) both require the stressor to occur in the six months before clinical onset. If the clinical onset of CMI occurred before the stressor, the factor cannot be used. The clinical onset is the time when symptoms first became sufficiently manifest to warrant diagnosis; it is not the date of formal diagnosis. A veteran whose symptoms began insidiously during deployment may need to prove that the onset was within six months after the stressor. If the onset predates the stressor, the factor fails.

The fifth trap is the narrowness of “hostile or life-threatening environment”. The three examples are all combat-related. A veteran who served in a peacekeeping mission in a hostile area but never went on combat patrols or faced artillery attacks may not qualify. The definition does not include being under threat of small arms fire in a non-combat setting, for example, or being kidnapped by militants. Those might fall under category 1A stressors if they meet the life-threatening event definition, but the 28-day duration factor is different.

The sixth trap is section 10(2) for factor (4) (inability to obtain appropriate clinical management). This factor applies only where the CMI was suffered or contracted before or during (but did not arise out of) the person’s relevant service, and only to material contribution or aggravation. This means that a veteran who developed CMI for the first time after service due to an inability to get clinical management cannot use this factor for the initial onset. The factor is designed for aggravation of a pre-existing condition that was not caused by service.

The seventh trap is the definition of “corpse” and “eyewitness”. The note states that seeing a closed body bag or viewing a body in an open-casket coffin is excluded. A veteran who viewed the aftermath of a suicide bombing where bodies were covered by tarpaulins may not meet the definition because they did not see the actual corpse. The exclusion of closed body bags is explicit. The “eyewitness” definition also excludes those exposed only to media coverage, which is relevant for veterans who saw graphic footage of atrocities on television or the internet.

The eighth trap is that the SoP is for reasonable hypothesis only. If the claim requires proof on the balance of probabilities (reasonable satisfaction), this SoP does not directly apply. A decision-maker may still refer to it as medical evidence, but it is not binding. Claimants who need to meet the higher standard must bring additional evidence that the factor actually caused the CMI, not merely that a reasonable hypothesis exists.

For a claimant (veteran or serving member) who believes they suffer from chronic multisymptom illness related to service, compliance with this SoP requires a structured approach. The first step is to obtain a diagnosis from a specialist physician or a psychiatrist. The specialist should be asked to address the three criteria: current symptoms from two of the three categories (fatigue; mood-cognition; musculoskeletal); that the symptom collection is distressing and significantly disrupts social and occupational functioning; and that it has persisted for at least six consecutive months. The specialist’s report should explicitly state that the diagnosis of chronic multisymptom illness is made in accordance with this Statement of Principles. If the specialist uses a different label (such as fibromyalgia or chronic fatigue syndrome), the report should map the symptoms to the SoP’s categories and confirm the functional impact.

The second step is to identify which of the four factors applies. For factor (1), the claimant must provide evidence of living or working in a hostile or life-threatening environment for at least 28 days in the six months before clinical onset. Service records showing deployment to a combat zone, patrol logs, incident reports, or a statement from the claimant describing combat patrols or exposure to artillery attacks can suffice. For factor (2) or (3), the claimant must prove that a category 1A or 1B stressor occurred within six months before clinical onset. Evidence may include mental health assessments, PTSD diagnoses, service documents, witness statements, or reports from military psychologists. The claimant must also show that the stressor satisfies the dictionary definitions: for a category 1B stressor involving viewing a corpse, the evidence must show that the claimant was an eyewitness (first-hand) and that the body was a corpse as defined (violent or horrific death, excluding closed body bags). For factor (4), the claimant must show that they were unable to obtain appropriate clinical management for CMI, and that this inability materially contributed to the aggravation of pre-existing CMI. This factor requires proof that clinical management was sought but not available, or that the claimant had reasonable access to treatment but was unable to obtain it due to service-related circumstances.

The third step is to establish the relationship to service under section 10(1): each factor must be related to the person’s relevant service. For example, a hostile environment factor must have been encountered during operational service, peacekeeping service or other relevant service; a stressor experienced on leave or after discharge will not succeed unless it is related to service.

For the death from CMI scenario (subsection 7(3)), the claimant must show that the chronic multisymptom illness contributed to a terminal event (pneumonia, respiratory failure, cardiac arrest, circulatory failure, cessation of brain function). Medical evidence linking CMI (potentially through dysautonomia or immune dysfunction) to the terminal event is required.

For decision-makers, compliance means systematically checking the diagnostic criteria against the medical evidence, verifying the specialist’s qualifications, and confirming that the symptom collection meets the definition. If the diagnosis is from a general practitioner, it must be rejected. If the claimant relies on factor (1), the decision-maker must calculate the 28-day period and confirm it falls within the six months before clinical onset. If the claimant relies on factor (2) or (3), the decision-maker must assess whether the event qualifies under the dictionary definitions. For example, a claim that a veteran saw dead bodies during a patrol after an IED attack may satisfy the definition if the bodies were visible and not in closed body bags. The decision-maker must also ensure that the factor is actually related to service; a stressor that occurred during a recreational activity off-base would not qualify.

For legal practitioners representing claimants, the key compliance strategy is to obtain a definitive specialist report early, ideally from a physician who understands the SoP’s three-category framework. If the claimant is still symptomatic, a psychiatrist may be able to diagnose both CMI and a stressor-related disorder, strengthening the claim. It is essential to document the clinical onset date precisely, as both the hostile environment and stressor factors require the factor to occur within six months before that onset. If the onset is unclear, the practitioner should gather all medical records showing the first mention of symptoms. Finally, practitioners should be aware of the interaction with other SoPs via section 11: if the factor itself (e.g., a category 1A stressor) constitutes a separate injury (e.g., PTSD), the claimant may also need to satisfy the PTSD SoP to prove that the stressor is related to service. This layered compliance is often overlooked.