This study will investigate the interactions between gender, behavior and psychopathology in the cocaine withdrawal syndrome. Anhedonia, cocaine craving, neuropsychological impairments and electrophysiological evidence of brain dysfunction may be manifestations of neuroadaptation in cocaine withdrawal, the evolution of which will be studied over a six month period of time. We will test 60 men and 60 women with a diagnosis of DSMIIIR cocaine dependence in the form of crack who are without other substance dependence diagnoses. Subjects will be recruited upon their entrance to residential treatment at Phoenix House, a large therapeutic community in New York City. This population is predominantly inner city minority, and contains many individuals who could be regarded as "hardcore" users of crack cocaine. Patients will be evaluated utilizing the SCID I and II, Cloninger's Tridimensional Personality Questionnaire (TPQ), The Hamilton and Beck Depression and Anxiety Scales, and Analog Craving Scale, a Structured Interview for Family History using RDC Criteria (FHRDC), the Sociopathy Checklist Revised (SCLR), a structured clinical database currently in use at Phoenix House as well as a brief neuropsychological battery testing memory and attention. Retention in treatment for crack cocaine dependence may be significantly affected by comorbid psychiatric symptoms and gender, with depression mediating treatment failure in females and antisocial personality traits mediating failure in males. We further predict that these two groups of treatment resistant patients will differ from subjects retained in treatment and from one another with respect to their pattern of scores on personality dimensions as conceptualized by the three dimensional model proposed by Cloninger. Differential electrophysiological profiles of these two groups of patients will also be sought.