Platelet monoamine oxidase activity and personality traits in alcoholics and methamphetamine dependents

Personality traits of alcoholics and methamphetamine dependents were examined by Karolinska scales of personality (KSP). The two groups differed with respect to Aggression, but, they were basically same in Impulsiveness. The biological marker platelet monoamine oxidase (MAO) activity showed a significant difference between the two groups. The low platelet MAO activity in alcoholics may suggest a certain biological basis to be involved in the etiology of dependence whereas the higher platelet MAO activity observed in methamphetamine dependents may reflect the prolonged use of methamphetamine and/or treatment with neuroleptics, or some biological basis.