We then conducted a Stage 2 randomized trial, which also evaluated CBT4CBT as an add-on to standard treatment, but took place in a more homogeneous but challenging sample: 101 cocaine-dependent methadone maintained individuals (Carroll et al., 2014). In this study, CBT4CBT plus standard treatment was significantly more effective in reducing cocaine use than standard methadone treatment alone over the 8-week course of treatment and its effects were maintained through a 6-month follow-up (Carroll et al., 2014). The evaluation of acquisition of coping skills demonstrated slightly different findings from the first trial, as a larger percentage of participants had baseline scores indicating relatively high levels of skill, which might be expected in a group that had been maintained on methadone for some time and thus had considerable prior exposure to CBT-based group treatment. Thus, while a significant treatment by time effect in acquisition of coping skills was not found for the full sample, it was present among the subgroup with lower baseline levels of skills (Kiluk et al., under review).
