Ontario Mental Health Act
The Ontario Mental Health Act (OMHA) is an Ontario law which regulates the administration of Mental Health Care. The main purpose of the law is to regulate the involuntary admission of people into a psychiatric hospital. Since the changes brought about in 2000 under Bill 68 (often referred to as Brian's Law, named after Brian Smith who was shot dead in 1995 by a person suffering from paranoid schizophrenia), the act allows for a community treatment order by the attending physician. This order is intended to provide comprehensive treatment outside of a psychiatric facility.

# Assessment orders
An individual can be brought into a hospital under three conditions. When a person is acting in a disorderly manner, the act allows the police to take someone to be examined by a physician if they believe that the person is a danger to himself or herself, a danger to others, or the person is not able to care for himself or herself. In situations where there is no immediate danger, anyone can bring evidence to a justice of the peace that the person is a danger to himself or herself, a danger to others, or is not able to care for himself or herself. The judge can then order a person to be examined by a physician and fill out a Form 2 authorizing the police to take the person to a physician for examination. Finally, any physician who has assessed a person within the last 7 days, and feels that the person may be a danger to himself or herself, a danger to others, or the person is not able to care for himself or herself, then the physician can order that the person undergo a psychiatric assessment by filling out a Form 1 authorizing the police to bring the person in for examination.

# Involuntary admissions
Once a person has been brought to a psychiatric facility to be assessed, the physician may hold them there for up to 72 hours on an application for psychiatric assessment (Form 1). This form allows the person to be held at a psychiatric facility for assessment, but does not itself permit any treatment without the persons consent, consent to treatment is not covered under the mental health act but rather the health care consent act. The physician must also fill out a Form 42 to notify the person and inform them of why they're being held.
At the end of the 72 hours permitted by a Form 1, the person must either be released, be admitted as a voluntary patient, or continue to be held as an involuntary patient with a certificate of involuntary admission (Form 3). The physician who signs the Form 3 must be different than the physician who signed the initial Form 1. A Form 3 allows the patient to be held for two weeks and the patient must be notified with a Form 30. At the end of the two weeks, if the facility is to continue to keep the patient on an involuntary basis, a certificate of renewal (Form 4) must be filled out. The first time a Form 4 is filled out, it is valid for one month, the second time it is filled out it is valid for two months, each time after that, it is valid for three months. Each time a Form 4 is filled out, another Form 30 must be filled out, notifying the patient.

## Rights of the patient
A physician who places a person on a Form 3 or Form 4 is required to notify a rights adviser who is required to meet with and explain to the patient what his or her rights are. If the patient requests it, a rights adviser will also help the patient apply for an appeal or acquire legal services.
If a patient is placed on a Form 3 or Form 4, they have the right to appeal the decision to a Consent and Capacity Board which will hear the patient's and physician's case. A patient's involuntary status is reviewed by the Board every year whether the patient requests it or not. The board is composed, at the minimum, of a lawyer, a psychiatrist, and a member of the community (often a family member of someone with mental illness).
If the patient or physician disagrees with the Board's decision, they may appeal to the Ontario Superior Court of Justice.

# Community treatment orders
The OMHA states that "the purpose of a community treatment order is to provide a person who suffers from a serious mental disorder with a comprehensive plan of community-based treatment or care and supervision that is less restrictive than being detained in a psychiatric facility. ...  to provide such a plan for a person who, as a result of his or her serious mental disorder, experiences this pattern: The person is admitted to a psychiatric facility where his or her condition is usually stabilized; after being released from the facility, the person often stops the treatment or care and supervision; the persons condition changes and, as a result, the person must be re-admitted to a psychiatric facility." 
When a physician decides that a patient meets the criteria for a community treatment order, a treatment plan is developed with the involvement of all people involved in the plan. In addition to the physician and the patient, people involved in the plan may include other health care workers, social workers, family members, the substitute decision maker, or others. Once the treatment plan is agreed to by all parties, the patient is required to follow the plan while living in the community. Failing to follow the plan can result in the person being readmitted to the hospital on a Form 1. One notable aspect of the community treatment orders is that it allows anyone who is named in the treatment plan to communicate with each other for the purpose of providing treatment, care, or supervision of the person. By removing barriers to communication between members of the health care team, appropriate interventions can be quickly applied when the person is at risk.
A community treatment order lasts six months and can be renewed if needed. A person on a community treatment order has the right to see a rights advisor and to appeal to the Consent and Capacity Board. The Board will review community treatment order every year whether the patient requests it or not.

# Miscellany
- Under the OMHA it is not permitted to administer psychosurgery to a patient who is considered incompetent to consent to treatment.