Sections of the Mental Health Act 1983

Patients can be detained under civil sections by doctors and social workers or under criminal sections by the courts or after release from prison. Individuals can also be the subject of community-based treatment instead of being detained in hospital.

Civil (non-forensic) sections

Individuals can be detained in hospital if it is recommended by their doctor.

Section 2: an individual can be detained in hospital for up to 28 days to be assessed, which may be followed by Section 3, if necessary. They have the right to a Tribunal, but need to apply within the first 14 days.
Section 3: allows an individual to be detained for up to six months for treatment. This can renewed for another six months and then yearly, with the right to a Tribunal.

Criminal (forensic) sections

These sections are concerned with:

Section 37: individuals who are tried at a Magistrates or Crown Court may be sentenced to six months in a secure hospital if they are unfit to plead. This can be renewed for another six months and then yearly, with the right to apply for release after the first six months.
Section 37/41: in very serious cases the Crown Court may add a restriction order to Section 37. Individuals subject to such a restriction can still be discharged by Tribunal, but conditions such as living in a specific place or undergoing treatment may be imposed.
Section 47: allows an individual in prison to be transferred to a secure hospital if recommended by two doctors. If discharged by a Tribunal, they will return to prison.
Section 48: individuals in prison on remand can be transferred to a secure hospital if recommended by two doctors. They still have the right to a Tribunal, but will return to prison if discharged.
Section 49: allows the Home Secretary to prevent an individual being discharged from hospital if they require further treatment, even if their sentence has finished. The Tribunal can only make recommendations for their discharge or future care.

Community sections

These allow people to live in the community or have periods of leave from hospital:

Section 17: enables a detained patient to have leave in the community, which may be supervised by a member of hospital staff.
Community Treatment Order: enables people to live in the community under certain conditions, such as taking medication or visiting medical professionals.