Mental capacity and psychiatric in-patients: implications for the new mental health law in England and Wales

Background In England and Wales mental health services need to take account of the Mental Capacity Act 2005 and the Mental Health Act 1983. The overlap between these two causes dilemmas for clinicians. Aims To describe the frequency and characteristics of patients who fall into two potentially anomalous groups: those who are not detained but lack mental capacity; and those who are detained but have mental capacity. Method Cross-sectional study of 200 patients admitted to psychiatric wards. We assessed mental capacity using a semi-structured interview, the MacArthur Competence Assessment Tool for Treatment (MacCAT–T). Results Of the in-patient sample, 24% were informal but lacked capacity: these patients felt more coerced and had greater levels of treatment refusal than informal participants with capacity. People detained under the Mental Health Act with capacity comprised a small group (6%) that was hard to characterise. Conclusions Our data suggest that psychiatrists in England and Wales need to take account of the Mental Capacity Act, and in particular best interests judgments and deprivation of liberty safeguards, more explicitly than is perhaps currently the case.