MHA 1983 s1

Mental Health Act 1983
(as amended)

Law as at 19/11/11

Part I contents


All Parts

I, II, III, IV, 4A, V, VI, VIII, IX, X, Schedules

See Definition of mental disorder.

Changes made by Mental Health Act 2007

Related cases

Any cases with a hyperlink to this legislation will automatically be added here. There may be other relevant cases without a hyperlink, so please check the mental health case law page.

See also

[The chapter/paragraph numbers here refer to the 2008 versions of the Code of Practice and Reference Guide.]


Application of Act: "mental disorder"

1.— (1) The provisions of this Act shall have effect with respect to the reception, care and treatment of mentally disordered patients, the management of their property and other related matters.

(2) In this Act—

["mental disorder" means any disorder or disability of the mind; and
"mentally disordered" shall be construed accordingly;][1]

and other expressions shall have the meanings assigned to them in section 145 below.

[(2A) But a person with learning disability shall not be considered by reason of that disability to be-

(a) suffering from mental disorder for the purposes of the provisions mentioned in subsection (2B) below; or
(b) requiring treatment in hospital for mental disorder for the purposes of sections 17E and 50 to 53 below,

unless that disability is associated with abnormally aggressive or seriously irresponsible conduct on his part.

(2B) The provisions are-

(a) sections 3, 7, 17A, 20 and 20A below;
(b) sections 35 to 38, 45A, 47, 48 and 51 below; and
(c) section 72(1)(b) and (c) and (4) below.][1]

[(3) Dependence on alcohol or drugs is not considered to be a disorder or disability of the mind for the purposes of subsection (2) above.][1]

[(4) In subsection (2A) above, "learning disability" means a state of arrested or incomplete development of the mind which includes significant impairment of intelligence and social functioning.][1]


  1. 1.0 1.1 1.2 1.3 1.4 Mental Health Act 2007 s1, s2, s3, s55 & sch 11; Mental Health Act 2007 (Commencement No.7 and Transitional Provisions) Order 2008 wef 3/11/08