The definition of mental disorder is changed by the MHA 2007, as of 3/11/08, so that it is no longer split into the four classifications of mental illness, psychopathic disorder, mental impairment and severe mental impairment.

s1 now states that:

"mental disorder" means any disorder or disability of the mind.

Related changes

There are, however, two exceptions. See these pages for details:

• Abnormally aggressive or seriously irresponsible conduct is only a consideration for learning disability (not personality disorder) 3/11/08 - Learning disability is not mental disorder unless associated with this conduct.

• Some exclusions to definition of mental disorder have been removed 3/11/08 - dependence on alcohol or drugs is still excluded.

Commencement

Date in force	Commencement order	MHA 2007 section	MHA 1983 sections affected
3/11/08	Mental Health Act 2007 (Commencement No. 6 and After-care under Supervision: Savings, Modifications and Transitional Provisions) Order 2008	Section 1 insofar as it gives effect to paragraph 13 of Schedule 1	s66
3/11/08	Mental Health Act 2007 (Commencement No.7 and Transitional Provisions) Order 2008	Remainder of section 1 and sch 1	s1, s3, s7, s20, s35, s36, s37, s38, s45A, s47, s48, s51, s72, s86, s141, s145. [Other Acts are amended, including MCA sch 4 para 23]
"	"	s55, sch 11	s1, s7, s11, s15, s16, s20, s21B, s27, s45A, s47, s55, s66, s72, s92; sched 1 part 1 para 2, 3, 6; sched 5 para 37, 39

Summary of effect of amendments in Chapter 1 of Part 1

Table from Explanatory Notes, page 9.

Provision	Currently applies to	Will apply in future to	Learning disability provision to apply in future	"Treatability" test applies now	Appropriate medical treatment test to apply in future
Civil Patients (Part 2 of the Act)
Admission for assessment for up to 28 days (section 2)	Mental disorder	Mental disorder	No	No	No
Admission for treatment (s3)	MI, MM, PD, SMM	Mental disorder	Yes	Yes	Yes
"Holding power" for patients already in hospital (s5)	Mental disorder	Mental disorder	No	No	No
Guardianship (s7)	MI, MM, PD, SMM	Mental disorder	Yes	No	No
Patients concerned in criminal proceedings (Part 3 of the Act)
Remand to hospital for report (s35)	MI, MM, PD, SMM	Mental disorder	Yes	No	Yes
Remand to hospital for treatment (s36)	MI, SMM	Mental disorder	Yes	No	Yes
Hospital order (s37)	MI, MM, PD, SMM	Mental disorder	Yes	Yes	Yes
Hospital order without conviction (s37(3) and 51(5))	MI, SMM	Mental disorder	Yes	No	Yes
Interim hospital order (s38)	MI, MM, PD, SMM	Mental disorder	Yes	No	Yes
Hospital and limitation directions (s45A)	PD	Mental disorder	Yes	Yes	Yes
Transfer direction - sentenced prisoner (s47)	MI, MM, PD, SMM	Mental disorder	Yes	Yes	Yes
Transfer direction - other (s48)	MI, SMM	Mental disorder	Yes	No	Yes

Key: MI = mental illness, MM = mental impairment, PD = psychopathic disorder, SMM = severe mental impairment

See also

• Reference Guide to the Mental Health Act 1983, 1. The structure of the Act and basic definitions