Prevalence and detection of serious psychiatric disorder in defendants attending court

Background Diversion programmes in magistratesʹ courts are designed to provide immediate advice or access to mental-health treatment facilities for defendants when appropriate. The prevalence of serious psychiatric disorder and the proportion of defendants who might require transfer are unknown. We undertook a study to address these issues and to find out whether defendants with such disorders are reliably detected by court personnel and referred to psychiatric staff in court diversion programmes. Methods A two-phase screening method used questionnaires for psychiatric disorder (the general health questionnaire and psychotic screening questionnaire) and screening instruments for alcohol and substance misuse followed by standard psychiatric interview (schedules for clinical assessment in neuropsychiatry). The detection rate of defendants with serious psychiatric disorder by court staff was observed. Findings The frequency of serious psychiatric disorder was 1·31% (three of 229) among defendants appearing in court direct from the community and 6·57% (96 of 1460) among those held in custody overnight. Of the 99 defendants with serious psychiatric disorder, 34 had schizophrenia and other psychoses and 55 had depressive disorders. 42 (76%) of the 55 individuals with depressive disorders had suicidal ideas, which were recorded on the first-phase screening questionnaire in many cases. Only 14 of 96 defendants from overnight custody with serious psychiatric disorder were detected by court staff and referred to the court diversion programme. Interpretation There is a substantial rate of psychiatric disorder in the court population, which is not satisfactorily detected with the current system. Brief screening questionnaires and training of court staff are probably necessary for detection of people with serious psychiatric disorder passing through the courts.