The primary objective of this study is to evaluate the efficacy of buspirone, relative to placebo, in preventing relapse in cocaine-dependent adults in inpatient/residential treatment who are planning to enter outpatient treatment upon inpatient/residential discharge. Secondary objectives include evaluating the impact of buspirone, relative to placebo, on other drug-abuse outcomes and on factors that may mediate buspirone's efficacy as a relapse-prevention treatment.