[Intellectual efficiency and drug addiction]

The intellectual efficiency of a group of drug addicts and a group of neurotic and senile subjects was tested against the Wechsler-Bellevue Intelligence Scale. Alongside an anxiety-related reduction in the efficiency of certain functions and a reduction in the ability to concentrate, the addicts evidenced a reduction in efficiency in the organisation of tasks and prediction of results related to depression of disharmony in the interaction of the various functions.