Mental Health Law comprises legal regulation of psychiatry and forensic psychiatry per se. The primary subject matter of legal regulation of psychiatry includes: (civil commitment, (2) confidentiality, (3) right to treatment and to refuse treatment, (4) informed consent, (5) professional responsibility and (6) professional ethics. Forensic psychiatry has both a civil and a criminal division. Civil forensic psychiatry addresses: (1) civil commitment, (2) child custody and related issues, (3) determination of the various civil competencies, (4) psychiatric disability, (5) psychiatric malpractice, and (6) personal injury litigation. Criminal forensic psychiatry addresses: (1) competency to stand trial, (2) sanity, (3) diminished capacity (where applicable), (4) voluntariness of confessions, (5) “death” cases, (6) “mens re” cases, and (7) prison mental health.
As with the law in general, mental health law is shaped by constitutional doctrine, state and federal statutes, administrative regulations, and court decisions. Constitutional doctrines and various landmark court decisions have been fundamental in shaping and re-shaping modern mental health law.
The 4th (search and seizure, probable cause) 5th (due process and related rights), 6th (right to an attorney), and 14th (Due Process and Equal Protection) Amendments to the US Constitution are the groundwork of much mental health law. The Equal Protection Clause has been pivotal because it applies whenever a law seeks to limit a group’s protections under the law. When a law does this, and in so doing limits a fundamental right, the government’s interest must be “compelling” and the method it uses must be “least onerous.”
Court’s adjudicate questions of law by interpreting the meaning of a law (statutory construction) or by declaring the principle of law that governs the outcome of a case before it. In special circumstances, the court may declare a statute unconstitutional and thus null and void. These decisions are afforded weight through the judicial doctrine of stare decisis.
When law calls on psychiatry for help, it often does so because of the nature of law. Society delegates to the legal system its interest in protecting the individual from injury by others, providing care for incompetents at risk because of their own negligence, and resolving disputes between parties fairly. It may call on psychiatry because it seeks to do justice and this demands it consider issues of intention, motivation, and moral accountability.
The psychiatrist who provides such assistance does so with special responsibility. She recognizes her duty is to the law and that there is no doctor-patient relationship. She is obliged to address all the facts, not just those supporting her opinion. She searches for disconfirming facts. She has a duty to obtain informed consent from the evaluee and to “re-consent” if she detects “slippage.” Her analysis must identify the legal question, the legal criteria that answers the question (this identifies the “psychiatry” of the case), the relevant data in the relevant time frame that she needs to discover; and she must explicate the reasoning process the underlies her conclusion. This reasoning process is governed by logic: an assertion of law, a statement of fact, and a conclusion reached by deduction. All of this must be informed by knowledge of the literature and relevant legal principles.
Civil commitment is a major focus of mental health law. It is a tool of government designed to provide psychiatric detention and coercive treatment. It is limited by statute and surveilled by the First, Fourth, Fifth, Sixth, and Fourteenth Amendments to the Constitution. A person cannot be detained or forcibly treated for the mere status of being mentally ill. A mentally ill person can be detained only if he/she poses a threat of serious, imminent harm to herself (Danger to Self) or others (Danger to Others) or is gravely disability (Grave Disability). These criteria have changed little since over the past four centuries; i.e. since well before the arrival of the psychiatrist. When introduced, detention was in amorphous institutions. Once institutionalized, the detainee was kept indefinitely and his/her property was transferred to the institution.
The modern power of civil commitment emerges from two societal doctrines: parens patriae and police power. Government is deemed to be the "parent of last resort" (parens patriae) with the responsibility to protect dependent "infants and lunatics." It is also given the power to act against those who pose a threat of harm to the community at large (police power). The Supreme Court of Massachusetts said in 1845 (Matter of Josiah Oaks), said "the right to restrain an insane person of his liberty is found in that great law of humanity, which makes it necessary to confine those ... dangerous to themselves or others...and the necessity which creates the law, creates the limitation of the law...restraint can continue as long as the necessity continues."
An early moidel commitment law was the 19th C. New York Field Code. This act provided for the care of the "quietly" insane and the "furiously" mad. The responsibility for the former was transferred by a court to a relative. The latter were placed in institutions until their "fury" abated.