All subjects were interviewed using the Semi-Structured Assessment for Drug Dependence and Alcoholism (SSADDA) (Gelernter et al., 2005; Pierucci-Lagha et al., 2005). A diagnosis of cocaine dependence was based on DSM-IV criteria, and CIP was defined by an affirmative answer to the question “Have you ever had a paranoid experience when you were using cocaine?” CIP is defined only in the context of cocaine use and most CIP subjects meet criteria for cocaine dependence as well. The overall reliability of this assessment of CIP is excellent (κ = 0.87) (Gelernter et al., 1994; Gelernter et al, 2005; Kalayasiri et al., 2006a). More information on the study sample is reported in Table 1.
