Neuropsychological deficits in 'primary' and 'secondary' non-medical drug users

An extensive neuropsychological test battery, specifically designed to investigate brain-behaviour relationships, was administered to two groups of multiple drug users. The 'primary' group consisted of subjects referred fundamentally on account of drug abuse problems. The 'secondary' group were referred principally for neurological reasons, but during history taking they reported drug use. Fifty patients, in all, were examined. Results showed that people who have received psychiatric care for drug abuse and who had started using drugs at an earlier age ('primary' group) had fewer adaptive resources and limited psychometric and academic achievement skills. This effect cannont be attributed to personality differences. Both groups had noticeably greater difficulties on motor tests, fine manipulative skills, and Halstead's Impairment Index when compared with a normal control group matched for age and sex.