title: Prevalence and predictors of mental incapacity in psychiatric in-patients.
abstract: BACKGROUND
  Little is known about the proportion of psychiatric in-patients who lack capacity to make treatment decisions, or the associations of lack of capacity.
  
  
  OBJECTIVE
  To determine the prevalence of psychiatric in-patients who lack capacity to make decisions about current treatment and to identify demographic and clinical associations with lack of mental capacity.
  
  
  METHODS
  Patients (n=112) were interviewed soon after admission to hospital and a binary judgement of capacity was made, guided by the MacArthur Competence Tool for Treatment. Demographic and clinical information was collected from an interview and case notes.
  
  
  RESULTS
  Of the 112 participants, 49 (43.8%) lacked treatment-related decisional capacity. Mania and psychosis, poor insight, delusions and Black and minority ethnic group were associated with mental incapacity. Of the 49 patients lacking capacity, 30 (61%) were detained under the Mental Health Act 1983. Of the 63 with capacity, 6 (9.5%) were detained.
  
  
  CONCLUSIONS
  Lack of treatment-related decisional capacity is a common but by no means inevitable correlate of admission to a psychiatric in-patient unit.
authors.affiliation: Academic Department of Psychological Medicine, Institute of Psychiatry, Weston Education Centre, 10 Cutcombe Road, London SE5 9RJ, UK.
authors.forename: Ruth
authors.initials: R
authors.lastname: Cairns
authors.forename: Clementine
authors.initials: C
authors.lastname: Maddock
authors.forename: Alec
authors.initials: A
authors.lastname: Buchanan
authors.forename: Anthony S
authors.initials: AS
authors.lastname: David
authors.forename: Peter
authors.initials: P
authors.lastname: Hayward
authors.forename: Genevra
authors.initials: G
authors.lastname: Richardson
authors.forename: George
authors.initials: G
authors.lastname: Szmukler
authors.forename: Matthew
authors.initials: M
authors.lastname: Hotopf
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000523:psychology; D044383:Black People; D003072:Cognition Disorders / Q000523:psychology; D003134:Commitment of Persons with Psychiatric Disorders; D003657:Decision Making; D003702:Delusions / Q000523:psychology; D005260:Female; D006760:Hospitalization; D006801:Humans; D007406:Interview, Psychological; D008297:Male; D016743:Mental Competency / Q000523:psychology*; D001523:Mental Disorders / Q000208:ethnology / Q000523:psychology*; D010358:Patient Participation / Q000523:psychology; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000523:psychology; D012720:Severity of Illness Index; D012959:Socioeconomic Factors