title: Mental capacity to make decisions on treatment in people admitted to psychiatric hospitals: cross sectional study.
abstract: OBJECTIVE
  To estimate the prevalence of mental capacity to make decisions on treatment in people from different diagnostic and legal groups admitted to psychiatric hospital.
  
  
  METHODS
  Cross sectional study.
  
  
  METHODS
  General adult acute psychiatric inpatient units.
  
  
  METHODS
  350 consecutive people admitted to psychiatric wards from the community over 16 months.
  
  
  METHODS
  Mental capacity assessed by clinical interview and the MacArthur competence assessment tool for treatment.
  
  
  RESULTS
  Estimates of mental capacity were obtained on 97% (n=338) of the 350 people admitted. Of those an estimated 60% (95% confidence interval 55% to 65%) lacked mental capacity to make decisions on treatment. This proportion varied according to diagnosis, ranging from 97% (n=36) in people with mania to 4% (n=24) in people with personality disorder. Mental incapacity was common in patients admitted informally to the psychiatric wards (n=188; 39%, 32% to 46%). Incapacity and detention are closely associated under non-capacity based mental health law.
  
  
  CONCLUSIONS
  Mental incapacity to make decisions on treatment is common in people admitted to psychiatric wards from the community but cannot be presumed. It is usual in those detained under the Mental Health Act and common in those admitted voluntarily.
authors.affiliation: Department of Psychological Medicine and Psychiatry, Institute of Psychiatry, King's College London, London SE5 8AF.
authors.forename: Gareth S
authors.initials: GS
authors.lastname: Owen
authors.forename: Genevra
authors.initials: G
authors.lastname: Richardson
authors.forename: Anthony S
authors.initials: AS
authors.lastname: David
authors.forename: George
authors.initials: G
authors.lastname: Szmukler
authors.forename: Peter
authors.initials: P
authors.lastname: Hayward
authors.forename: Matthew
authors.initials: M
authors.lastname: Hotopf
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D003657:Decision Making; D004739:England; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006778:Hospitals, Psychiatric / Q000706:statistics & numerical data; D006801:Humans; D007258:Informed Consent; D008297:Male; D016743:Mental Competency; D001523:Mental Disorders / Q000523:psychology*; D008605:Mental Health Services / Q000706:statistics & numerical data*; D014852:Wales