An accused's mental health condition may be relevant to a proceedings in several ways. An accused who is "unable on account of mental disorder to conduct a defence" or is unable "to instruct counsel" may be unfit to stand trial. An accused who was at the time of the offence "incapable of appreciating the nature and quality of the act or omission or of knowing that it was wrong" may be subject to a finding of "Not Criminally Responsible".
Finally, certain jurisdictions have a specialized mental health court system that diverts certain cases that involve offences that sufficiently relate to a mental illness and are amendable to some form of treatment and supervision.
Certain provinces have legislation that permits court ordered assessments of the accused where he has reason to believe he has a mental disorder.
- see PART XX.1
e.g. s. 21 of the Mental Health Act, RSO 1990, c M.7, s 21