What is Mental Health?

Legal Definition
Mental health is a level of psychological well-being, or an absence of mental illness. It is the "psychological state of someone who is functioning at a satisfactory level of emotional and behavioral adjustment". From the perspective of positive psychology or holism, mental health may include an individual's ability to enjoy life, and create a balance between life activities and efforts to achieve psychological resilience.

According to the World Health Organization (WHO), mental health includes "subjective well-being, perceived self-efficacy, autonomy, competence, inter-generational dependence, and self-actualization of one's intellectual and emotional potential, among others." The WHO further states that the well-being of an individual is encompassed in the realization of their abilities, coping with normal stresses of life, productive work and contribution to their community. Cultural differences, subjective assessments, and competing professional theories all affect how "mental health" is defined. A widely accepted definition of health by mental health specialists is psychoanalyst Sigmund Freud's definition: the capacity "to work and to love".
-- Wikipedia
Legal Definition
Mental health and the law interact in numerous ways. The term "competence" signifies a legal conclusion that an individual is capable of entering into a binding contract, transferring assets, or participating in a legal proceeding. The provision of mental health services is regulated and, to some extent, publicly supported.

Legal standards surround the process by which those who are mentally ill can be forced, against their will, to receive treatment. Statutes for involuntary commitment whether denominated civil or criminal are subject to the due process clause of the 14th Amendment. This is because involuntary commitment severely infringes on a person's right to be free from governmental restraint and the right to not be confined unnecessarily. Courts have held that such statutes must bear some reasonable relation to the purpose for which the individual is committed.

Finally and most conspicuously, the criminal justice system has, of necessity, to address issues of responsibility, appropriateness of trial and treatment in the light of mental health considerations.

States dictate how and when the insanity defense may be invoked in state court while the federal government does so for the federal court system. In 1984, the Insanity Defense Reform Act (18 U.S.C. ยง 17) was passed. Generally, it placed the burden of proving insanity on the defendant and it cut on the use of mental illness as a defense. Today, insanity is rarely invoked and of those, only a quarter succeed.