Mental health law provides the body of legislature that helps define whether or not someone possesses the mental capability of acting in a legally competent manner. Typically, this has to do with psychiatric disorders such as dementia, psychosis, or schizophrenia. The law also covers how mental health patients are to be treated. In Canada, provinces often follow different legislations for their hospitals and medical system, i.e. Ontario follows the Ontario Mental Health Act. This topic includes concepts such as mens rea, informed consent, automatism, insanity defences, and legal definitions of relevant terms. These relevant terms can include 'sanity', 'insanity', 'competent', and 'incompetent'. But, not all countries have mental health laws. In Europe, 96% of countries have some legislation surrounding mental health, whereas in the Eastern Mediterranean, only 59% have legislation (1).
1) Presence of mental health policies and legislation, The World Health Report 2001, chap. 4, fig. 4.1.