Decreased platelet monoamine oxidase activity in female anorexia nervosa

Objective: To study if platelet MAO activity, previously described as a serotonergic index, is modified in a sample of pure restrictive anorectic patients. Method: Twenty-five female patients with DSM-IV anorexia nervosa restricting type were studied and compared with 30 healthy female controls. Platelet MAO activity was measured by isotopic methods using C-14 benzylamine. Impulsive personality features were measured with specific rating scales and temperament studied with Cloninger's TCI. Results: Platelet MAO activity was significantly lower (4.3 + 2.7 nmol/h/108 platelets) in the anorectic patients than in the control group (6.7 + 2.8) (P< 0.01). Platelet MAO was inversely correlated with scores on impulsivity scales and positively correlated with the dimension 'persistence' of Cloninger's TCI. Conclusion: Platelet MAO activity is lowered in a group of patients with anorexia nervosa and might involve some dysfunction in the regulation of impulse control.