Few criminal defences are as widely misunderstood as the "insanity defence." Television and high-profile trials often portray it as a loophole that lets a person walk free. The reality is the opposite: in Canada the defence is narrow, highly technical, rarely successful, and can lead to state control that lasts longer than a criminal sentence would have.
The first thing to know is a matter of vocabulary. Canada does not have an "insanity" verdict. The legal concept is Not Criminally Responsible on Account of Mental Disorder (NCRMD) , set out in section 16 of the Criminal Code and administered through Part XX.1 (Mental Disorder). NCRMD is different from arguing that the Crown failed to prove the mental state (mens rea) required for the offence , and it differs from the intoxication defence because self-induced intoxication is generally not a "disease of the mind."
The defence is also rare: studies consistently find it is raised in well under 1% of criminal cases, and only a portion of those end in an NCRMD verdict. Public attention spiked after the 2021 trial of Alek Minassian for the 2018 Toronto van attack. He argued he was not criminally responsible on the basis of autism-spectrum thinking, but the court rejected the argument and found him criminally responsible on all counts — a clear illustration of how high the threshold is.
Modern Canadian law traces to the M'Naghten Rules , developed in England in the 1840s, which exempted an accused who, because of a "defect of reason from disease of the mind," did not understand the nature and quality of the act or did not know it was wrong. Canada first codified an insanity defence in the 1892 Criminal Code . Early law was punitive — those found insane were often detained indefinitely "at the pleasure of" provincial authorities. Late-20th-century reforms replaced that with today's Part XX.1 framework, which emphasizes public safety, proportionality, and treatment over punishment.
The defence is codified in section 16 of the Criminal Code :
16(1) No person is criminally responsible for an act committed or an omission made while suffering from a mental disorder that rendered the person incapable of appreciating the nature and quality of the act or omission or of knowing that it was wrong.
Subsections 16(2) and (3) add the procedural rules: everyone is presumed not to have an exempting mental disorder, and the burden is on whichever party raises the issue to prove it on a balance of probabilities . So the defence has a two-part test — the accused must have been incapable either of appreciating the nature and quality of the act or of knowing it was wrong — set against a presumption of capacity.
One point the statute does not spell out is what "wrong" means. The Supreme Court of Canada has held that it means morally wrong , judged by the ordinary standards of society — not merely "against the law" ( R. v. Chaulk , [1990] 3 SCR 1303). It is not enough that the accused knew the act was illegal; the question is whether a mental disorder left them unable to know the act was something they ought not to do, and unable to apply that understanding to the specific act ( R. v. Oommen , [1994] 2 SCR 507).
The Criminal Code defines a mental disorder as a "disease of the mind" — a legal concept, not simply a medical diagnosis, which courts interpret narrowly. Temporary emotional states, self-induced intoxication, personality traits, or moral failings do not qualify on their own.
Conditions that may meet the threshold include schizophrenia and other psychotic disorders, severe bipolar disorder with psychotic features, major depressive disorder with psychosis, and certain severe delusional disorders. But a diagnosis alone is never enough: conditions such as autism, ADHD, or personality disorders generally do not satisfy s. 16 unless accompanied by a qualifying impairment that meets the two-part test at the time of the offence.
NCRMD and unfitness to stand trial are frequently confused, but they address different moments in time.
| NCRMD | Unfit to stand trial | |
|---|---|---|
| Focus | Mental state at the time of the offence | Mental state during the proceedings |
| Question | Was the accused criminally responsible? | Can the accused participate in their own trial? |
| Result | A verdict of not criminally responsible | Proceedings are paused until fitness is restored |
Under s. 2 of the Criminal Code , a person is unfit to stand trial if, because of a mental disorder, they cannot understand the nature or object of the proceedings, understand the possible consequences, or communicate with counsel. When fitness is in doubt, a court can order a psychiatric assessment and hold a fitness hearing. A person found unfit may be ordered into treatment to restore fitness and referred to the Review Board; if fitness cannot be restored and they are not a significant threat, proceedings may eventually be stayed.
An NCRMD finding is a verdict (s. 672.34): the person committed the act but is not criminally responsible for it. It is not an acquittal, and it does not lead to automatic release. Instead, the case moves into Part XX.1 and, in most cases, to a provincial or territorial Review Board — in Ontario, the Ontario Review Board.
When a court or Review Board makes a disposition under s. 672.54 , it must choose the disposition that is necessary and appropriate in the circumstances , taking into account the safety of the public, which is the paramount consideration , together with the accused's mental condition, their reintegration into society, and their other needs. There are three possible dispositions:
The Review Board must review most dispositions at least once every 12 months ( s. 672.81 ), with limited exceptions allowing longer intervals. One note on the standard: older guides describe a "least onerous and least restrictive" test, but since 2014 the Criminal Code asks for the disposition that is necessary and appropriate , with public safety paramount.
"A finding of NCRMD transfers control from the criminal courts to a mental health tribunal, often for years."
— Heather Spence, Criminal Defence Lawyer & Partner
NCRMD must be proven by the party raising it — usually the defence, though the Crown can raise mental disorder in some circumstances. That party must establish, on a balance of probabilities, that a qualifying mental disorder existed and that it met the s. 16 test at the time of the offence. In practice this almost always requires psychiatric expert testimony, medical records, and evidence of behaviour before, during, and after the offence. The Crown frequently responds with its own experts and with circumstantial evidence — planning, concealment, or awareness — suggesting the accused did understand what they were doing.
Even when it succeeds, NCRMD is not a path to freedom. It can bring potentially lengthy — sometimes indefinite — supervision or hospital detention, ongoing conditions and restrictions, repeated Review Board hearings, and significant stigma and loss of autonomy. In some cases a person found NCRMD remains under state control longer than they would have spent in custody had they simply been convicted and sentenced.
"The insanity defence is not an escape hatch — it is a transfer into a different, and often longer, legal regime."
— Robbie Tsang, Criminal Defence Lawyer & Managing Partner
Because the consequences are so serious, experienced counsel approach NCRMD cautiously — usually considering it only when the evidence of mental disorder is strong, conventional defences are unlikely to succeed, and the client's long-term mental-health needs genuinely outweigh a penal outcome. In many files a Charter challenge, an evidentiary weakness, a lesser-included offence, or another resolution is the better route. That is why the Toronto criminal defence lawyers at Mass Tsang weigh mental-health issues case by case before raising s. 16. If you or a loved one is facing charges that involve mental illness, getting informed legal advice early is essential.
It is legally called Not Criminally Responsible on Account of Mental Disorder (NCRMD) . Under s. 16 of the Criminal Code , a person is not criminally responsible if, because of a mental disorder at the time of the offence, they were incapable of appreciating the nature and quality of the act or of knowing it was wrong.
NCRMD means the accused committed the act but is not criminally responsible for it because of a qualifying mental disorder. It is a verdict, not an acquittal, and it does not automatically result in release.
The party raising the defence — usually the accused — must prove, on a balance of probabilities , that a mental disorder existed and met the s. 16 test at the time of the offence.
No. Unfitness is about the ability to understand and participate in the trial ; NCRMD is about the accused's mental state when the offence was committed .
The case goes to a provincial Review Board, which orders an absolute discharge (required where the person is not a significant threat to public safety), a conditional discharge , or detention in a hospital — with public safety as the paramount consideration (s. 672.54).
Not necessarily. A person found NCRMD can remain under Review Board supervision for years and, in some cases, longer than they would have served in prison if convicted.
