Mental capacity to consent to treatment in anorexia nervosa: explorative study

BACKGROUND Mental capacity to consent to treatment in anorexia nervosa is a neglected area in clinical decision-making. AIMS To examine clinical and neuropsychological parameters associated with diminished mental capacity in anorexia nervosa. METHOD An explorative study was conducted in 70 adult female patients with severe anorexia nervosa. Mental capacity to consent to treatment was assessed by experienced psychiatrists. Further measurements included the MacCAT-T (to assess mental capacity status), a range of clinical measures (body mass index (BMI) and comorbidity) and neuropsychological tests assessing decision-making, central coherence and set-shifting capacity. RESULTS Diminished mental capacity occurs in a third of patients with severe anorexia nervosa and is associated with a low BMI, less appreciation of illness and treatment, previous treatment for anorexia nervosa, low social functioning and poor set shifting. CONCLUSIONS Assessment of diminished mental capacity in anorexia nervosa requires careful evaluation of not only BMI, but also the degree of appreciation of illness and treatment, history and the tendency to have a rigid thinking style. DECLARATION OF INTEREST None. COPYRIGHT AND USAGE © The Royal College of Psychiatrists 2016. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence.