Compared to never users, current cocaine/heroin users scored higher on Neuroticism and lower on Conscientiousness (see Table 4). Former cocaine/heroin users scored lower on Conscientiousness, but did not differ from never-users on Neuroticism. On the facet level, current users scored high on all facets of Neuroticism, with large effect sizes (difference larger than one SD) on N6:Vulnerability, high on E5:Excitement Seeking, low on A1:Trust, A2:Straightforwardness, and A4:Compliance, and very low on all facets of Conscientiousness, with differences larger than one SD on C1:Competence, C4:Achievement Striving, and C6:Deliberation. The profile of cocaine/heroin current users is illustrated in Figure 1, which resembles the pattern seen for current smokers, but the profile of cocaine/heroin users is more extreme. Additional analyses indicated that although the few individuals (n = 9) who used both cocaine and heroin had the most extreme profile, the individuals who were current users of cocaine but not heroin also scored significantly higher on Neuroticism and lower on Conscientiousness than never users.
