Adult Psychiatric Reports


Fitness to stand trial, insanity, other mental state defences


Insanity is a legal term defined in Section 23 of the Crimes Act 1961 as follows:

  1. Everyone shall be presumed to be sane at the time of doing or omitting any act until the contrary is proved.
  2. No person shall be convicted of an offence by reason of an act done or omitted by him or her when labouring under natural imbecility or disease of the mind to such an extent as to render him or her incapable—
    1. of understanding the nature and quality of the act or omission; or
    2. of knowing that the act or omission was morally wrong, having regard to the commonly accepted standards of right and wrong.
  3. Insanity before or after the time when he or she did or omitted the act, and insane delusions, though only partial, may be evidence that the offender was, at the time when he or she did or omitted the act, in such a condition of mind as to render him or her irresponsible for the act or omission.
  4. The fact that by virtue of this section any person has not been or is not liable to be convicted of an offence shall not affect the question whether any other person who is alleged to be a party to that offence is guilty of that offence.

The defence of insanity shields the defendant from criminal conviction, and results in an acquittal. However, the defendant may still be detained, if necessary, and their mental disorder treated.

Section 4 of the Criminal Procedure (Mentally Impaired Persons) Act 2003 (CPMIPA) provides that “unfit to stand trial, in relation to a defendant,—

  1. means a defendant who is unable, due to mental impairment, to conduct a defence or to instruct counsel to do so; and
  2. includes a defendant who, due to mental impairment, is unable—
    1. to plead:
    2. to adequately understand the nature or purpose or possible consequences of the proceedings:
    3. to communicate adequately with counsel for the purposes of conducting a defence.

Section 14 of the Act requires that the Court must receive the evidence of 2 Health Assessors in order to determine the issue.

In addition to reports in relation to insanity and fitness to stand trial, Forensic Psychiatrists may provide evidence on a number of other issues relevant to the mens rea of a defendant, including issues relating to intoxication and automatism, as well as competence to instruct counsel.

Steven Yannoulidis’ book, Mental State Defences in Criminal Law, provides an excellent guide to psychiatric issues in relation to criminal trials, and is relevant both to the defence and prosecution lawyers.  See for a review of this excellent book.

Mental disabilities may also be relevant to police interviews, for instance in the case of defendants with Fetal Alcohol Spectrum Disorder (FASD) or defendants with intellectual disability which may make them vulnerable to self-incrimination in the interview process. This was relevant to the Privy Council’s ruling quashing the convictions of Teina Pora. provides a guide to Fetal Alcohol Spectrum Disorder.

Psychiatric issues such as schizophrenia, depression, bipolar disorder, substance abuse, intoxication, alcoholic blackouts, neurocognitive and anxiety disorders may also impact upon witnesses and other participants in the Court process. Our experts have provided expert witness testimony in a range of settings and on a wide range of topics.


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