METHOD

The study sample comprised 10 male chronic cocaine abusers (mean±SD age, 26.7±3.5 years; weight, 182±29 lb) who met the DSM-III-R diagnostic critena for cocaine abuse. The criteria for inclusion of a patient in the study were as follows: at least a 6-month history of use of free-base cocaine, use of a minimum of 4 g of cocaine per week over the past 6 months, no previous history or evidence of intravenous cocaine use, a lack of dependence on any drug other than cocaine, and a lack of evidence for psychiatric, neurological, or medical problems not related to cocaine. The patients were referred from outpatient detoxification clinics. Seven subjects were each tested 2-7 days after the last cocaine dose, and three were tested 4-5 weeks after the last cocaine dose. Table 1 gives demographic and clinical characteristics of the patients. The control group comprised 10 male healthy volunteers(age, 28.1±3.0 years; weight, 165±8 lb) with no history of drug abuse or psychiatric or neurological disease. None of the patients or control subjects took medication during this study.