Twenty healthy chronic cocaine abusers and 20 age-, gender-, and education-matched healthy control subjects participated in this study (Table 1). Participants were recruited from advertisements on public bulletin boards, in local newspapers, and by word-of-mouth. Eligible subjects were scheduled for an onsite evaluation that included a full physical and neurological examination by a neurologist. All subjects provided written informed consent as approved by the local Institutional Review Board (Stony Brook University's Committee on Research Involving Human Subjects, CORIHS), and were screened for absence of medical, psychiatric or neurological diseases. A clinical psychologist conducted a semi-structured diagnostic interview which included the Structured Clinical Interview for DSM-IV Axis I Disorders [research version [21], [22]] and the Addiction Severity Index [23].
