Psychoactive drugs and stimulus analysis: IV. The experimental discrimination of acute and prophylactic antidepressants

Abstract

Lithium, a drug used in the prophylactic control of recurrent depression, and tranylcypromine, a monoamine oxidase inhibiting agent used acutely to treat ongoing depressive episodes, are examined in a behavioural test designed to give information about drug effects upon stimulus analysis and motor activity, with appropriate adjustments being made for state dependence and memory effects. Neither drug has marked effects on motor activity according to the results of the test, but whereas lithium suppresses stimulus analysis, tranylcypromine appears to stimulate that function. The results are discussed in the context of a model of affective disorders based on stimulus analysis dysfunction.