Abstract
The authors examined cognitive and psychological differences between cocaine- and opiate-dependent individuals, using the Symptom Check List-90-Revised (SCL-90-R) and the Shipley Institute of Living Scale (SILS). They studied a sample of 135 cocaine-dependent and 162 opiate-dependent patients entering drug abuse treatment studies at the National Institute on Drug Abuse-Addiction Research Center (NIDA-ARC) outpatient clinic. Cocaine-dependent patients had significantly higher estimated Wechsler Adult Intelligence Scale (WAIS-R) IQ, vocabulary, abstraction, and total T scores, as measured by the SILS. On the SCL-90-R, cocaine-dependent patients had significantly higher scores for interpersonal sensitivity, anxiety, phobic anxiety, paranoid ideation, and psychoticism; opiate-dependent patients had higher scores for somatization. The results suggest that cocaine-dependent patients have better cognitive function and more psychopathology than opiate-dependent patients entering drug abuse outpatient treatment studies.