Subjects who were at least 18 years of age were assessed with the structured clinical interview for DSM disorders and screened for drugs in urine. All patients had a clinical diagnosis of CA as defined by DSM-IV. All psychiatric axis I disorders except alcohol dependence and nicotine dependence were used as exclusion criteria [5]. In addition, participants were excluded if they had a history of a seizure disorder (except cocaine-induced seizures) or a severe medical illness, including a history of AIDS. DNA samples for the control populations were collected from University of Pennsylvania, Thomas Jefferson University [9] and the National Institute of Mental Health Genetics Initiative (NIMH-GI). Control individuals were screened for history of substance use disorders and other psychiatric illnesses. They were not assessed with a urine drug screen and ethnicity was determined by self-report.
