This Guide was prepared by Borden Ladner Gervais LLP for the Ontario Hospital Association (OHA). The fourth edition was authored by Katharine Byrick and Barbara Walker-Renshaw In June 2023. This resource provides a general understanding of mental health law issues in several key areas, such as consent to treatment, involuntary admission, community treatment orders, the detention and supervision of mentally disordered criminal offenders, along with an overview of the provincial and federal legislation that governs the provision of mental health care in Ontario. (c) 2023 by Ontario Hospital Association. All rights reserved.