Acute and protracted cocaine abstinence in an outpatient population: a prospective study of mood, sleep and withdrawal symptoms.

This study addresses unresolved questions about cocaine withdrawal by prospectively assessing monitored cocaine abstinence over 28 days in a sample of 24 male and female cocaine-dependent outpatients. Based on results from urine drug screens and self-reported substance use, it is likely that these patients were abstinent from cocaine during the assessment period. Abstinence-related symptoms were monitored at 2, 5, 10, 14, 21, and 28 days following last cocaine use. For patients who were known to relapse, assessments began again after the last day of cocaine use. Consistent with findings from inpatient studies of cocaine abstinence, linear improvements in negative affect, low cocaine craving, and increases in cognitive skills were reported over the 28 days. Also consistent with inpatient studies of cocaine withdrawal, a phasic withdrawal syndrome was not observed in this outpatient sample. Unlike inpatient studies, no disturbances in sleep were reported.