TSC v Department for Health and Wellbeing

The Supreme Court of South Australia heard an appeal from a decision of the South Australian Civil and Administrative Tribunal. The appeal concerned a level 2 community treatment order made in respect of the applicant, who has a primary diagnosis of schizophrenia and a comorbid diagnosis of PTSD. The applicant accepted the PTSD diagnosis but not the schizophrenia diagnosis. He had been subject to community treatment orders since 2016 and had previously been admitted to hospital as an involuntary patient following behaviour indicative of his mental illness, including non-compliance with prescribed psychiatric medication.

The central legal issue before the Court was whether the Tribunal had erred in its determination that the applicant possessed impaired decision-making capacity concerning his mental illness, as defined by sections 16(1) and 5A(2) of the *Mental Health Act 2009* (SA). This required an analysis of the statutory concept of impaired decision-making capacity and its application to the applicant's circumstances, particularly in relation to his understanding and use of information relevant to his treatment.

The Court affirmed the Tribunal's interpretation of impaired decision-making capacity, which drew upon principles established in *PBU & NJE v Mental Health Tribunal*. The Tribunal had correctly stated that capacity requires understanding, retaining, and using relevant information to make a decision, and communicating that decision. The Court noted that a person could still have capacity even if their decisions were considered illogical or irrational by others, and that the assessment should focus on capacity rather than behaviour. The Court found that the concepts of understanding and using information overlapped, and that a failure to understand some information did not automatically equate to an inability to understand or use it, although the totality of evidence could support such a conclusion.

The Court concluded that the Tribunal did not err in the inferences it drew from the evidence presented. Consequently, its finding that the applicant had impaired decision-making capacity was not affected by error. Leave to appeal was granted, but the appeal itself was dismissed.