3%) found a highly significant difference (χ2(1) = 7.26; p = 0.009), indicating a reduction in cocaine use over time. Effect sizes were calculated to establish possible effects of the prizeCM. The total number of cocaine-free days during study time was compared between the two groups, resulting in an effect size of d = 0.14, displaying a weak effect for prizeCM. Forty-nine of 60 participants (81.7%; EG: n = 25; CG: n = 24) attended the 6-month follow-up visit ( Fig. 1). The percentage of cocaine-negative urine samples at 6-month follow-up was higher in the EG, although EPZ6438 statistically not significant

(EG: 65.5% vs. CG: 45.2%; Fig. 4). Self-report continuous cocaine abstinence did not differ between the two groups even though patients in the EG achieved on average of 11.54 (SD = 9.06) weeks compared to 7.83 (SD = 8.97) weeks in the CG. No difference between the groups was found in self-report measures of cocaine use, frequency (past 7 days), amount (in gram) and cocaine craving scores. Repeated-measures ANOVAs at follow-up showed a significant decrease in frequency of cocaine Selleck ABT 888 use over time (F(1.93/55.87) = 5.95, p = 0.005), but no group difference. Furthermore, a reduction in the amount of cocaine use (F(2.04/59.08) = 2.861: p = 0.064) was found. Although this failed to reach statistical significance, it might be seen as a trend in favor

of the EG. In the ITT sample, all clinical measures (BDI, SDS, ASI composite scores) did not differ significantly between groups during the entire 24-week trial. For patients remaining in the study, ASI composite scores decreased significantly, indicating a relevant reduction in the severity of drug use (F(3/96) = 39.73; p = 0.000), alcohol use (F(3/96) = 4.42; p = 0.006), employment (F(3/93) = 4.67; p = 0.004) and psychiatric problems (F(3/96) = 6.31;

p = 0.001), but without any differences between groups. Three areas remained unchanged (legal, family and medical problems). BDI (F(3/93) = 12.74; p = 0.000) and SDS scores (F(3/90) = 33.45; p = 0.000) decreased significantly over time without any group differences. There was no significant difference in the number of attended CBT sessions between the groups. Patients in the EG attended on average 12.86 (SD = 5.7) sessions and those in the CG 11.68 (SD = 6.04) sessions (maximum 18 sessions). Patients’ crotamiton satisfaction with the CBT sessions after 12 and 24 weeks did not vary between groups. The question “Are you satisfied with the therapy?” was rated with a mean score of 4.78 after 12 weeks (EG = 4.81; CG = 4.75) and a mean score of 4.7 after 24 weeks (EG = 4.79; CG = 4.61), indicating a high satisfaction with CBT. The question “Did the therapy help you?” was rated with a mean score of 4.44 after 12 weeks (EG = 4.33; CG = 4.55) and 4.65 after 24 weeks (EG = 4.68; CG = 4.61), displaying a strong belief that therapy helped. The general question “How do you feel now compared to study start” was asked after week 12 and after week 24.