1. On 21 March 2025 the employer (the appellant), lodged an Application to Appeal Against the Decision of a Medical Assessor. The medical dispute was assessed by

Dr Yu Tang Shen, a Medical Assessor, who issued a Medical Assessment Certificate (MAC) on 21 February 2025. 2. The appellant relies on the following grounds of appeal under s 327(3) of the Workplace Injury Management and Workers Compensation Act 1998 (the 1998 Act): * the assessment was made on the basis of incorrect criteria, and * the MAC contains a demonstrable error. 3. The delegate is satisfied that, on the face of the application, at least one ground of appeal has been made out. The Appeal Panel has conducted a review of the original medical assessment but limited to the grounds of appeal on which the appeal is made. 4. Rule 128 of the Personal Injury Commission Rules 2021 (the PIC Rules) and Procedural Direction PIC7 - Appeals, reviews, reconsiderations and correction of obvious errors in medical disputes set out the practice and procedure in relation to the medical appeal process under s 328 of the 1998 Act. An Appeal Panel determines its own procedures in accordance with r 128(1) of the PIC Rules. 5. The assessment of permanent impairment is conducted in accordance with the SIRA NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment, 4th ed

1 March 2021 (the Guidelines) and the American Medical Association Guides to the Evaluation of Permanent Impairment, 5th ed (AMA 5).

1. The Appeal Panel conducted a preliminary review of the original medical assessment in the absence of the parties and in accordance with the Procedural Direction PIC7.
2. The appellant did not request that the worker undergo a re-examination. As a result of its preliminary review, the Appeal Panel determined that it was not necessary for the worker to undergo a further medical examination because the Appeal Panel did not find error, and absent a finding of error, the Appeal Panel has no power to require the worker to undergo a re-examination.

1. The Appeal Panel has before it all the documents that were sent to the Medical Assessor for the original medical assessment and has taken them into account in making this determination.

1. The parts of the medical certificate given by the Medical Assessor that are relevant to the appeal are set out, where relevant, in the body of this decision.

1. Both parties made written submissions. They are not repeated in full, but have been considered by the Appeal Panel.

1. The procedures on appeal are contained in s 328 of the 1998 Act. The appeal is to be by way of review of the original medical assessment but the review is limited to the grounds of appeal on which the appeal is made.
2. In Campbelltown City Council v Vegan [2006] NSWCA 284 the Court of Appeal held that the Appeal Panel is obliged to give reasons. Where there are disputes of fact it may be necessary to refer to evidence or other material on which findings are based, but the extent to which this is necessary will vary from case to case. Where more than one conclusion is open, it will be necessary to explain why one conclusion is preferred. On the other hand, the reasons need not be extensive or provide a detailed explanation of the criteria applied by the medical professionals in reaching a professional judgement.
3. The matter was referred to the Medical Assessor for assessment as follows:

**"**The following matters have been referred for assessment (s 319 of the 1998 Act):

• Date of injury: 24 May 2017
• Body parts/systems referred: Psychiatric/psychological disorders
• Method of assessment: Whole person impairment"

1. The Medical Assessor issued a MAC certifying as follows:

page and paragraph number in NSW workers compensation guidelines

Chapter, page, paragraph, figure and table numbers in AMA5 Guides

WPI deductions pursuant to S323 for pre-existing injury, condition or abnormality (expressed as a fraction)

Sub-total/s % WPI (after any deductions in column 6)

Total % WPI (the Combined Table values of all sub-totals)

There is a pre-existing impairment deduction of 1/10th

There has not been any significant improvement in function from treatment, so no adjustments for the effect of treatment has been made.

1. The assessment was based on his assessment under the psychiatric impairment rating scale (PIRS) as required by the Guidelines as follows (emphasis in original):

Since the subject injury, he said he is showering once a week and he requires support from his wife to prompt him to shower, and he is no longer cooking, cleaning, or laundry, or lawn care. He said he has not been shopping.

As he has needed prompting from his wife for self-care he has moderate impairment.

Since the subject injury, he said he has lost lots of his friends, and he has few friends, including his brother, his three sisters, a "best mate" and his wife and children. He sees his three sisters once a year, he sees his brother a few months ago, and his brother will see him soon. He said he sees his "best mate" who visits him 2-3 times a year, as he lives 8 hours away. He said they don't talk, but they spend time together and he has found his "best mate" a major support for him. He said he is no longer attending any social events at all and doesn't leave the front gate if he can help it.

As he has been socially isolated, though spends time occasionally with friends, he has moderate impairment.

He said he has not been driving, and he said his wife drives him.

As he relies on his wife for transport, he has moderate impairment.

Since the subject injury, he said his relationship with his wife has been strained, without any physical violence, and no periods of separation. He said he has been doing his best to be a father for his children, and he said he is spending time with his daughter and tries to get his cognitive function to communicate with her, and they might go for a walk. He has not been able to drive them anywhere. He said his relationship with his stepchildren have been good. He said he rings his brother daily.

Since the subject injury, he said he has lost lots of his friends, and he has few friends, including his brother, his three sisters, a "best mate" and his wife and children. He sees his three sisters once a year, he sees his brother a few months ago, and his brother will see him soon. He said he sees his "best mate" who visits him 2-3 times a year, as he lives 8 hours away. He said they don't talk, but they spend time together and he has found his "best mate" a major support for him. He said he is no longer attending any social events at all and doesn't leave the front gate if he can help it.

As he has maintained a strained and distant relationship with his wife, children and siblings, and a friend, he has mild impairment.

Since the subject injury, he said his concentration has been poor, and he struggles to sustain a conversation, and he loses his train of thought quickly.

He spoke articulately and frequently overinclusive and tangential at times. He required constant redirection to ensure that he provided responses to the questions posed to him. He was alert, and disorganised in his thoughts, and forgetful.

As he had disorganised thinking and forgetfulness evident in a brief conversation, he has severe impairment.

Since the subject injury, he has not been able to work.

There is a pre-existing impairment deduction of 1/10th

There has not been any significant improvement in function from treatment, so no adjustments for the effect of treatment have been made"

1. The employer appealed.
2. In summary, the appellant submitted that the Medical Assessor made assessments on the basis of incorrect criteria and/or made demonstrable errors and accordingly, the MAC should be revoked by the Appeal Panel who should make a further deduction of one-half from the Medical Assessor's impairment assessment of 23% whole person impairment (WPI) in accordance with the assessment made by Dr Bisht, IME qualified on behalf of the appellant, to take account of the impairment from a secondary psychological injury.
3. In summary, the respondent worker Dayle Spencer (the respondent) submitted that the Medical Assessor did not err or make an assessment on the basis of incorrect criteria and the MAC should be confirmed.
4. The role of the Medical Assessor is to conduct an independent assessment on the day of examination. The Medical Assessor is required to take a history, conduct a mental state examination, make a psychiatric diagnosis and have due regard to other evidence and other medical opinion that is before the Medical Assessor. The Medical Assessor must bring his clinical expertise to bear and exercise his clinical judgement when making an independent assessment of impairment under the PIRS categories. The Appeal Panel notes that there is no challenge to the ratings of impairment in each of the six PIRS categories.
5. The path of reasoning disclosed by the Medical Assessor must be adequate. This is also dependent on the extent of the history taken and a thorough examination of the worker so that self- report can be properly evaluated in the context of other evidence before the Medical Assessor.
6. The Medical Assessor took a history which he recorded as follows (emphasis in original):

"● Brief history of the incident/onset of symptoms and of subsequent related events, including treatment:

He said on the day of the subject injury, 24 May 2017, the brake was locked on and heated up, and the inside tyre burst and caught alight. He said he was nearby and it exploded, and he rang the fire brigade. He said he was on the main street of Moree. He said they turned around and went up the bypass. He said that he got out from underneath and coughing out, and the other tyre 'went boom'. He said the back tyre was still up and heated up and both tyres exploded, hit the fuel tank and hit the truck. He said he had butane canisters inside the passenger seat in the truck. He said he got most of the things out, and he was getting his second doona out, and a bit of molten rubber landed on his forearm. He thought he was alright, and the truck was black. He said he rubbed the molten rubber off his arm. He said there was water on the passenger seat. He said afterwards, he woke up on the tar, coughing and spitting, with two people standing over him. He said he doesn't know what happened while he had lost consciousness.

He said after the subject accident, he developed psychological symptoms, including not being able to 'help myself out'.

He said he has seen psychologists, psychiatrist, drugs and alcohol counsellors, and he said nothing has helped him, apart from using a diary. He said that after the subject accident, he went to St John of God Richmond seven times over 7 years.

He said he was not sure what medications he was currently on.

He is not currently seeing his psychiatrist, who has left St John of God.

He has been trying to find where his previous psychiatrist has moved to.

He said he has been drinking alcohol up to daily use, up to 1 bottle of rum and more. He said he had abstained 2 years ago for 14 months, and prior to an assessment, he broke down and started drinking again. He is currently drinking 3-5 days a week, up to a bottle of rum or more. He said he has been using medicinal cannabis every day. He said he has not been using any other substances.

He said he has a lot of intrusive recollection of the subject accident, and nightmares of the subject incident, which causes him to wake up in distress. He said he writes about it in his diary, and he tells anybody everything to deal with his, and he said he avoids driving and avoids trucks that remind him of the accident. He said he cannot trust other people, and he said it took a long time for him to learn to trust his wife again. He has a constant feeling of shame and guilt. He has a diminished interest in his previous activities, and he feels detached from friends and family, and has difficulties experiencing positive emotions. He has been more frequently angry and agitated. He has been hypervigilant, and has disturbed sleep and poor concentration.

He said he has been feeling depressed all the time, about how his life has changed, and how this has impacted on his family. His sleep has been poor, and he has been sleeping 4 hours or less at night. His appetite has been poor, and he has lost some weight. His energy has been 'non-existent', and 'as motivated as a fence post'. He said he feels worthless and guilty all the time. He said he has suicidal ideations every day, and he feels he doesn't want to be alive, as he feels sick of dealing with his issues, and he said the only thing keeping him around is his wife.

She was asked if she had any other relevant information she wished to add, and she indicated that she did not have any further information to add.

• Details of any previous or subsequent accidents, injuries or condition:

Prior to the subject injury, he said his concentration was good, and he would be able to run his own business, and he would need to manage his BAS regularly, and he would be able to sustain his concentration driving a truck for up to 50 hours straight. Since the subject injury, he said his concentration has been poor, and he struggles to sustain a conversation, and he loses his train of thought quickly.

Prior the subject injury, he said he had trauma in his life, and he has had depression, anxiety and suicide, and he had rehabilitation and saw counsellors. He said he was in rehabilitation in 1990, after a previous fiancé died in a car accident in 1989. He said he learned a lot and he 'accepted a lot'. He said his psychiatric symptoms subsided in 1991, and he said he had no psychiatric symptoms in the interval period until the subject injury.

Prior to the subject injury, he said in 1990, he was using cannabis, cigarettes, alcohol and speed, and he had treatment in rehabilitation, and he said his substance use went into remission around 1991. He denied any substance use in the interval period, though he would occasionally drink alcohol.

He said there is a family history of excessive alcohol use in his parents.

Prior to the subject injury, he said he had a previous back injury, and degenerative disc disorder.

• Work history including previous work history if relevant:

He said he completed to the Year 10 equivalent, then he completed his welding apprenticeship.

Prior to the subject injury, he worked running his own business in Spanners and Home maintenance, and he was a qualified welder, and he said he would work over 80 hours a week, and he said he had a good work performance.

Since the subject injury, he has not been able to work.

He is 58 years old and lives in Cowra with his wife of over 15 years, and his 15-year-old-son and 6-year-old daughter. He has 3 stepchildren, who do not live with him, but he has previously been able to raise them. He has one brother, and 2 stepbrothers and a stepsister, and his father is still alive.

Prior to the subject injury, he said his relationship with his wife was good, and he said that his relationship with his children was good as well.

Since the subject injury, he said his relationship with his wife has been strained, without any physical violence, and no periods of separation. He said he has been doing his best to be a father for his children, and he said he is spending time with his daughter and tries to get his cognitive function to communicate with her, and they might go for a walk. He has not been able to drive them anywhere. He said his relationship with his stepchildren have been good. He said he rings his brother daily.

Prior to the subject injury, he said he had many friends, and he would see them 1-2 days a week. He said he would go fishing and camping with them, and they would drive out together.

Since the subject injury, he said he has lost lots of his friends, and he has few friends, including his brother, his three sisters, a 'best mate' and his wife and children. He sees his three sisters once a year, he sees his brother a few months ago, and his brother will see him soon. He said he sees his 'best mate' who visits him 2-3 times a year, as he lives 8 hours away. He said they don't talk, but they spend time together and he has found his 'best mate' a major support for him. He said he is no longer attending any social events at all and doesn't leave the front gate if he can help it.

Prior to the subject injury, he said he would shower twice a day, and he cook and clean regularly, do the lawn and cut trees. He said he would go shopping regularly. He said he was able to drive without restrictions.

Since the subject injury, he said he is showering once a week and he requires support from his wife to prompt him to shower, and he is no longer cooking, cleaning, or laundry, or lawn care. He said he has not been shopping. He said he has not been driving, and he said his wife drives him.

He was born in Narendra, and he said there were some adverse childhood experiences, but he was able to cope with them. He said he captained the school football teams at school."

1. The Appeal Panel is satisfied that an adequately detailed history was taken, which is broadly consistent with the other evidence before the Medical Assessor. Medical Assessors have to obtain a focussed history and undertake a mental state assessment within a finite appointment time.
2. The Medical Assessor undertook a mental state examination of which he recorded:

"He presented as a casually dressed and mildly dishevelled man. He had an average build and appeared to be his stated age.

He displayed some emotional reactivity and became teary at times during the interview.

He spoke articulately and frequently overinclusive and tangential at times. He required constant redirection to ensure that he provided responses to the questions posed to him.

He complained of intrusive recollections of the subject accident.

He had pessimistic thoughts of guilt and worthlessness, and suicidal ideations with no plans.

He was alert, and disorganised in his thoughts, and forgetful."

1. The Medical Assessor summarised the injury and diagnosis as follows (emphasis in original):

• ➢ Posttraumatic Stress Disorder, due to meeting Criterion A via exposure to the subject accident; meeting Criterion B due to experiencing symptoms of intrusive recollections and distressing dreams related to the subject accident; meeting Criterion C due to avoidance of potential triggers; meeting Criterion D due to a persistent feeling of shame and guilt, lack of trust of other people, marked diminished interest in his previous activities, feeling detached from family and friends, difficulties experiencing positive emotions; meeting Criterion E due to irritability, hypervigilance, sleep disturbances, and problems with concentration; meeting Criterion F as the duration of his symptoms are more than 1 month; meeting Criterion G as he has had significant distress and there has been impairment with his social and occupational functioning; and meeting Criterion H as these conditions are not wholly attributable to any other conditions.
• ➢ Persistent Depressive Disorder, due to meeting Criterion A with his depressed mood; Criterion B due to appetite changes, insomnia, anergia, low self-esteem, reduced concentration and feelings of hopelessness; meeting Criterion C as he has complained of persistent depressive symptoms over the course of the past few years; meeting Criterion D as there has been depressive symptoms longer than 2 years, and Criterion E and F have been met due to absence of manic episodes or psychosis; and meeting Criterion G as this episode is not attributable to another condition or effect of a substance; and Criterion H has been met due to significant functional impairment.
• ➢ Aggravation of Alcohol Use Disorder, with an escalation of his alcohol use, which was controlled until the subject injury.
• ➢ Aggravation of Cannabis Use Disorder.

The history obtained from the claimant was consistent with the prior medical reports. During the assessment, this claimant's presentation was consistent and appropriate."

1. The Medical Assessor made an assessment of WPI in accordance with his assessment under the six PIRS categories as set out above. The Appeal Panel notes that there is no challenge to the PIRS assessments.
2. He explained the facts on which his assessment was based and the reasons for the assessment as follows:

The facts on which I have based my assessment of whole person impairment are:

The information he provided in the interview, my observations of hin during the course of the interview, and the medical records provided to me.

1. My opinion and assessment of whole person impairment

In making that assessment I have taken account of the following matters:-

The information from the assessment and my observations of her, which can be found above, as well as information from the relevant documents, which have been summarised below:

The letter written by Dr Prudence Greenwell, general practitioner, dated 28 June 2017.

The claimant was involved in a truck accident where he was pulled from a burning truck and nearly died. He had a right shoulder and knee injury. He has been very anxious, not sleeping, avoiding driving and feels he cannot get into a truck again. He was on Cipramil 20mg a day and Coversyl.

Discharge summary from St John of God Hospital Richmond, dated 30 August 2018.

He was diagnosed with Posttraumatic Stress Disorder with secondary Alcohol and Marijuana Use Disorder. He was pulled from a burning truck. He had physical abuse as a child. His fiancé died in a motor vehicle accident. He progressed well in the admission and his wife was due to give birth in October.

Assessment summary from St John of God Hospital, dated 5 February 2019.

The claimant was an ex-truck driver. He had two children and lives in Cowra. He was pulled from a truck fire 20 months prior and has not worked since. Other stressors include having a new baby and reduced libido, increased alcohol use for the past two weeks drinking six drinks a day, his best friend's dad is sick, various financial stressors, his wife was threatening to leave him and his wife's mother had passed away. He had ongoing intermittent panic attacks. His past psychiatric history included having a three month rehab admission after his fiancé's death in 1990 and he had been seeing a psychologist and psychiatrist.

Addendum to the discharge summary, dated 30 August 2018.

His medication included Diazepam 5mg, Escitalopram 20mg and Thiamine 300mg. He was following up with a psychologist and psychiatrist on discharge.

Discharge summary from St John of God Hospital, dated 21 March 2019.

He was diagnosed with Posttraumatic Stress Disorder with Alcohol Use Disorder following the subject accident. He was on Escitalopram 20mg, Diazepam 5mg and Clonazepam as needed. He was followed up with his general practitioner, psychologist, drugs and alcohol support and psychiatrist.

Discharge summary from St John of God Hospital, dated 3 September 2019.

He was admitted with a diagnosis of Posttraumatic Stress Disorder with suicidal ideation and Alcohol Use Disorder. He remained on Escitalopram increased to 30mg, Lithium 125mg and Clonazepam as needed.

The letter written by Dr Prudence Greenwell, general practitioner, dated 9 September 2019.

The claimant has been suffering from Posttraumatic Stress Disorder since the subject accident. He has been seeing his psychologist, Jenny Duggan and a psychiatrist, Dr Jacobsen and has had three admissions to St John of God Hospital. He also has an alcohol problem. He has two children and a supportive wife. He has ongoing anxiety and blackouts. He was on Clonazepam 0.5mg as needed, Lexam 20mg, Lithium 250mg ½ a tablet per day.

The letter written by Dr Paul Stevenson, psychiatrist, dated 6 December 2019.

The claimant was diagnosed with cognitive impairment. He presented quite distressed. It was hard to get a good history from him. He had been abstinent from alcohol for three weeks. He was on Clonazepam 0.5mg in the morning and 1mg nightly, Panadeine Forte, Metoprolol, Mirtazapine 22.5mg nightly and Lithium 125mg in the morning.

The report written by Corrine Roberts, neuropsychologist, dated 4 September 2020.

His pre-morbid intellectual ability was in the average range. He had fluctuating attention and working memory with reduced speed of information processing. His short term memory fluctuated and was easily overwhelmed. He had good planning in a structured situation but was slow to complete tasks. He struggled to sustain his mental effort.

The report written by Dr Yajuvendra Bisht, psychiatrist, dated 11 July 2022.

He was unable to provide malingering or exaggerated symptoms. The claimant had reached maximum medical improvement, however, he was not able to provide a whole person impairment.

The report written by Dr Yajuvendra Bisht, psychiatrist, dated 27 October 2022.

He was diagnosed with Posttraumatic Stress Disorder, Major Depressive Disorder and alcohol dependence.

The report written by Dr Yajuvendra Bisht, psychiatrist, dated 10 January 2023.

Self-care and personal hygiene were mildly impaired. He was able to shop for himself but not particular with grooming. Social and recreational activities was moderately impaired. He does not attend social gatherings. Travel was mildly impaired as he cannot travel without support to unfamiliar places but able to travel to familiar places on his own such as the local shops. Social functioning was mildly impaired as his relationship with his family was affected. His concentration was moderately impaired as he was not able to read more than a few lines before losing concentration. Employability was severely impaired. His whole person impairment was 17% with a deduction for pre-morbid condition of 1.7% with a final whole person impairment of 15% with a deduction of 50% for a physical injury, with a whole person impairment 8%.

The report written by Dr Joanne Holdaway, psychiatrist, dated 30 October 2023.

He was diagnosed with Posttraumatic Stress Disorder , Persistent Depressive Disorder (Dysthymia), Alcohol Use Disorder and a provisional diagnosis of Somatic Symptom Disorder. There was a possible mild to moderate neurocognitive impairment with a mini mental state exam of 27/30 with subject difficulty with cognitive functioning. Self-care was moderately impaired, social and recreational activities was moderately impaired, travel was moderately impaired, social functioning was mildly impaired, concentration was severely impaired and employability was totally impaired with a whole person impairment of 26% with a deduction for pre-existing impairment with a final whole person impairment of 18%.

The report written by Dr Yajuvendra Bisht, psychiatrist, dated 5 June 2024.

1. In respect of the deduction under s 323 the Medical Assessor said as follows:

"Is any proportion of loss of efficient use or impairment or whole person impairment, due to a previous injury, pre-existing condition or abnormality? He has had a previous history of anxiety and depression and substance use, which resolved with treatment and was in remission prior to the subject injury.

If so, please indicate which body part/system is affected by the previous injury, pre-existing condition or abnormality. Psychiatric."

"11.DEDUCTION (IF ANY) FOR THE PROPORTION OF THE IMPAIRMENT THAT IS DUE TO PREVIOUS INJURY OR PRE-EXISTING CONDITION OR ABNORMALITY

1. In my opinion the worker suffers from the following relevant previous injuries, pre-existing conditions or abnormalities:

(i) Depression and anxiety

(ii) Substance use disorder

1. The previous injury, pre-existing condition or abnormality directly contributes to the following matters that were taken into account when assessing the whole person impairment that results from the injury, being the matters taken into account in 10a, and in the following ways:

(i) He has had a previous depressive disorder and substance use disorder (with cannabis, alcohol and stimulants), which occurred after the death of his fiancé in 1989, and for which he was treated with counselling and rehabilitation, and was quiescent following successful treatment until the subject injury. However, his prior depressive disorder and substance use disorder can be seen to have recurred as a consequence of the subject injury. It consequently contributes to his current psychiatric impairment, in that if he had not suffered his earlier depressive disorder and substance use disorder, his current impairment would not be as great.

1. The extent of the deduction is difficult or costly to determine so in applying the provisions of s.323(2) I assess the deductible proportion as one tenth. (can only be used when not at odds with available evidence)."

1. Having referred more extensively to the other medical opinion and evidence before him as set above, the Medical Assessors then made a brief comment on the other opinions as follows:

"My assessment is similar to Dr Holdaway, and differs from Dr Bisht, in that I have attributed much of his impairment to his psychiatric injury, as that alone can account for the degree of impairment he currently experiences."

1. The appellant pointed to the assessment of the IME qualified to provide an opinion on behalf of the respondent worker Dr Holdaway who had also assessed an overall impairment of 26% (consistent with the Medical Assessor and there is no complaint on appeal about the assessment of overall impairment at 26%WPI) but who proceeded to make a series of deductions as follows:

Further reductions: 1/10th escalation of anxiety from breathing issues

1/10th non-psych component to difficulties with cognitive function)."

1. The appellant submitted (emphasis in original):

"Notably, two 1/10th deductions were considered by Dr Holdaway (ie 20% apportionment) in accounting for impairment assessable under the PIRS Tables which did not result from the respondent's worker's primary psychological injury. Rather this impairment was considered to have resulted from a secondary psychological condition or otherwise to have resulted from physical/pathology injury, such that it was not considered to have been assessable as a result of the workers primary psychological injury."

1. The appellant also pointed to the opinion of Dr Bisht, the IME qualified to provide an opinion on behalf of the appellant who assessed an overall impairment of 17% WPI and then made a s 323 deduction and then made a further reduction of 50% for secondary psychological condition noting substantial ramifications from physical injury, giving a final assessment of 8% WPI (which led to the decline of the claim for lump sum compensation by the insurer).
2. The appellant quoted Dr Bisht as follows:

"The psychiatric injury is a combination of a primary injury as a result of the psychological trauma of the subject incident and secondary injury, consequent to the worker has continued to suffer from substantial ramifications of the physical injury and has needed extensive treatment, I would conclude that the proportionate contribution of the two components is 50 per cent each."

1. The appellant submitted that the Medical Assessor "erred in failing to consider the apportionment of impairment arising from a secondary psychological injury which both of the parties' independent medical experts considered to be appropriate in this case".
2. The appellant went onto submit (emphasis in original):

"It is the appellant's submission that whilst MA Shen has considered 'much of his impairment' could be attributed to the respondent worker's psychiatric injury, no attempt is made, or explanation is provided, in differentiating between the primary psychiatric injury, and, secondary psychiatric injury. In fact, the reference to 'much' rather than a term such as 'all' or 'the totality' suggest that a portion of the impairment may not have been related to the primary psychological injury and thus an apportionment ought to have been made."

1. The appellant seeks that an apportionment of 50% be made by the Appeal Panel in line with the assessment of Dr Bisht as follows:

"the appellant submits that the assessment provided by MA Shen ought to have included an apportionment of impairment arising from the respondent worker's primary psychological injury and secondary psychological injury. The appellant submits that the apportionment applied ought to have been 50% as considered by Dr Yajuvendar Bisht."

1. This would result in a final assessment of 12% WPI (26% WPI less one-tenth is 23% reduced by 50% leaves 12% WPI after rounding).
2. The appellant went onto submit that the failure to give adequate reasons amounted to demonstrable error as follows:

"further, and in the alternative, if the MA considered there ought to be no apportionment account for the effects of any secondary condition, the appellant submits that MA Shen ought to have provided more clear and detailed reasons, especially given his view was contrary to that of both of the parties' independently qualified psychiatrists."

1. The Appeal Panel notes that there is no determination by the Commission that the respondent worker suffers from a secondary psychological condition.
2. The role of the Medical Assessor is an independent one. He has to make his assessment independently of the other opinions before him. He is clearly cognisant of the opinions of

Dr Holdaway and Dr Bisht because he refers to both reports in their salient respects. The MAC must be read as a whole. 3. The Medical Assessor after obtaining a detailed history broadly consistent with the other evidence before him, conducting a through mental state examination and having had due regard to the other evidence before him has made a diagnosis of the psychological injury as follows:

• ➢ Posttraumatic Stress Disorder, due to meeting Criterion A via exposure to the subject accident; meeting Criterion B due to experiencing symptoms of intrusive recollections and distressing dreams related to the subject accident; meeting Criterion C due to avoidance of potential triggers; meeting Criterion D due to a persistent feeling of shame and guilt, lack of trust of other people, marked diminished interest in his previous activities, feeling detached from family and friends, difficulties experiencing positive emotions; meeting Criterion E due to irritability, hypervigilance, sleep disturbances, and problems with concentration; meeting Criterion F as the duration of his symptoms are more than 1 month; meeting Criterion G as he has had significant distress and there has been impairment with his social and occupational functioning; and meeting Criterion H as these conditions are not wholly attributable to any other conditions.
• ➢ Persistent Depressive Disorder, due to meeting Criterion A with his depressed mood; Criterion B due to appetite changes, insomnia, anergia, low self-esteem, reduced concentration and feelings of hopelessness; meeting Criterion C as he has complained of persistent depressive symptoms over the course of the past few years; meeting Criterion D as there has been depressive symptoms longer than 2 years, and Criterion E and F have been met due to absence of manic episodes or psychosis; and meeting Criterion G as this episode is not attributable to another condition or effect of a substance; and Criterion H has been met due to significant functional impairment.
• ➢ Aggravation of Alcohol Use Disorder, with an escalation of his alcohol use, which was controlled until the subject injury.
• ➢ Aggravation of Cannabis Use Disorder."

1. The Medical Assessor has noted the consistency of the workers presentation with the other evidence before him as follows:

The history obtained from the claimant was consistent with the prior medical reports. During the assessment, this claimant's presentation was consistent and appropriate."

1. The approach that the appellant advocates for namely a reduction of 50% after the application of the deduction by the Medical Assessor under s 323 for the pre-existing condition (about which there is no complaint on appeal) is not consistent with the correct application of the criteria in the Guidelines, s 65A and nor is it consistent with the authorities. Neither Dr Holdaway nor Dr Bisht approached the assessment correctly.
2. The correct approach is laid out by Basten JA in Matheson v Baptistcare re NSW & ACT [2025] NSWSC 213 (Matheson).
3. The assessment of the effects of a secondary psychological condition is not approached as a fraction of the overall impairment assessment but as a matter to be disregarded in assessing the permanent impairment resulting from the primary psychological injury: see Basten JA in Matheson at paragraph 50.
4. In Matheson Basten JA pointed out:

"49 The legal basis for the "deduction" made by the appeal panel must be found in s 65A of the Workers Compensation Act:

65A Special provisions for psychological and psychiatric injury

(1) No compensation is payable under this Division in respect of permanent impairment that results from a secondary psychological injury.

(2) In assessing the degree of permanent impairment that results from a physical injury or primary psychological injury, no regard is to be had to any impairment or symptoms resulting from a secondary psychological injury.

...

(5) In this section -

primary psychological injury means a psychological injury that is not a secondary psychological injury.

psychological injury includes psychiatric injury.

secondary psychological injury means a psychological injury to the extent that it arises as a consequence of, or secondary to, a physical injury.

1. As can be seen from s 65A(2), impairment resulting from a secondary psychological injury is not so much a basis for a deduction as a matter to be disregarded in assessing the permanent impairment resulting from the primary psychological injury. One consequence of this approach is that both must be assessed on the correct basis, namely by application of the Guidelines."
2. Basten JA went onto say:

"55 In stating that 'no regard is to be had to any impairment or symptoms resulting from a secondary psychological injury', s 65A(2) is badly worded: it does not require the medical assessor to have no regard to such impairment or symptoms; on the contrary, they are to be identified so as to exclude them from the assessment process. That exercise must be undertaken in conjunction with the assessment of the degree of permanent impairment attributable to the primary psychological injury the subject of the claim. Thus, a secondary psychological injury is to be identified and then disregarded in calculating the degree of permanent impairment arising from the injury the subject of the claim."

1. The Medical Assessor's assessment is one that is undertaken independently of the IMEs opinions before him. The Medical Assessor did not find that the worker suffered a secondary psychological condition (and there was no finding of the Commission to this effect). What the Medical Assessor diagnosed is a psychological injury most notably in the form of post-traumatic stress disorder as well as persistent depressive disorder, aggravation of alcohol use disorder and aggravation of substance use disorder.
2. It is clear when the MAC is read as a whole that the assessments made by the Medical Assessor under each of the PIRS categories result from the impairment that arises because of the psychiatric injury of post-traumatic stress disorder, persistent depressive disorder, aggravation of alcohol use disorder and aggravation of cannabis use disorder. The contribution of the pre-existing conditions (that is the condition which pre-existed the subject injury) (depression and anxiety, alcohol use disorder and cannabis use disorder) to the overall level of permanent impairment assessed have been appropriately taken into account in the one-tenth deduction made under s 323.
3. It was not open to the Medical Assessor to make a further reduction for conditions which did not pre-exist the injury.
4. His role was to assess the impairment from the referred psychiatric injury. He has made it clear that the impairment he has assessed in the PIRS categories results from the referred psychological injury and not his physical injury, and his psychological injury alone accounts for his impairment rated in the PIRS. This assessment when the MAC is read as a whole accords with the diagnosis made as a result of the referred psychiatric injury. He has had appropriate regard to the other opinions before him but he is not bound to follow them.
5. It is clear from the reasons given by the Medical Assessor that he was cognisant on the opinions of the IMEs Dr Bisht and Dr Holdaway but a fractional deduction cannot be made as they have done. Whilst s 65A(2) requires that impairments from any secondary psychological injury be disregarded, it does not mean that a Medical Assessor is to disregard the impairments if they are also result from the primary psychological injury. To do so in a case where the impairments from the primary psychological injury and any secondary psychological injury are so intermingled or indivisible, would risk an improper assessment of the impairment from the primary psychological injury because it would mean that, in disregarding impairment that may result from a secondary psychological injury, the impairment from the primary psychological injury has been disregarded inappropriately as well. It is evident from the Medical Assessor's clinical findings on the day of examination that his assessment of impairment results from the psychological conditions diagnosed by the Medical Assessor. Any impairment that relates from any secondary psychological condition is so intermingled with, or indivisible from, the impairment from the primary psychological condition that the Medical Assessor has appropriately assessed the impairment as resulting from the referred primary psychological injury. It is clear from the Medical Assessor's reasons, which the Appeal Panel considers adequate, that this was the approach of the Medical Assessor in this case and the Appeal Panel can discern no error.
6. For these reasons, the Appeal Panel has determined that the MAC issued on