Platelet MAO activity and personality characteristics. A study in schizophrenic patients and normal individuals.

Low levels of platelet monoamine oxidase have been found in schizophrenic and bipolar depressive patients. The enzyme activity seems to correlate negatively with certain personality traits (social activity, sensation seeking, hypomania, positive affect and monotony avoidance) which are correlated to some extent with the score "extraversion" from the Eysenck Personality Questionnaire (EPQ). The present study was carried out in an attempt to investigate further the possible correlation between platelet MAO activity and the personality traits measured by the EPQ. 41 schizophrenic patients and 20 healthy probands were blindly examined for platelet MAO activity and personality characteristics. The enzyme activity was found to correlate negatively with the extraversion score in patients and healthy probands, which is in agreement with the data from other studies. This correlation is discussed and a hypothesis suggested.