Platelet MAO activity in personality disorders and normal controls.

Platelet monoamine oxidase (MAO) activity has been related to several psychiatric disorders and personality dimensions. The purpose of this study was to measure platelet MAO activity in personality disorders and determine its relationship to symptoms analogous to sensation seeking. Twenty-eight males admitted to a psychiatric unit with a DSM-III-R diagnosis of personality disorder were compared to normal controls. Patients with Axis I diagnoses other than adjustment disorder were excluded. There was no difference in MAO activity between patients and normals, although it was lower in borderline patients. MAO activity was inversely correlated with sensation seeking, especially in the patient group, as predicted. The results are consistent with the view that platelet MAO activity is a marker of general psychopathology.