A Transtheoretical Model Group Therapy for Cocaine

Background and Purpose: This research tested a novel and innovative behavioral group therapy for cocaine based on the Transtheoretical Model of behavior change (TTM). In Phase 1 investigators modified "Group Treatment for Substance Abuse: A Stages-of-Change Therapy Manual" (Velasquez, Maurer, Crouch & DiClemente, 2001) to specifically target cocaine abuse, resulting in a twelve-session group intervention and accompanying therapy manual based on the TTM stages and processes of change. Six “early stage" sessions targeted the experiential processes of change (POC), and six “later stage” sessions targeted the behavioral POC. In Phase 2 we conducted a randomized trial with cocaine abusing clients, comparing the TTM group therapy to an education/advice comparison group. This study extends our team's research on interventions using the TTM and is the first to develop and evaluate an intervention based on the TTM's 10 experiential and behavioral processes of change. The primary research questions were:

1. Is the TTM group therapy acceptable to clients? This was measured by client adherence, retention, and treatment satisfaction.

2. Did client outcomes improve over the course of treatment? This was measured using the Timeline Followback for cocaine.

This study also measured the effect of the TTM group therapy on proposed mechanisms of change as identified in the TTM, thereby testing whether:

a) TTM group therapy increases processes of change use compared to the comparison group.

b) increased process use promotes stage of change movement

c) process use and stage movement enhance retention and diminish drug use.

Methods: The TTM intervention was informed by focus groups with recovering substance abusers and expert researchers. It incorporated motivational interviewing, relapse prevention, and other strategies to facilitate clients' use of POC. We employed a randomized, controlled, between groups design in which cocaine abusers (N=138) were assigned to one of two group treatment conditions: TTM therapy or Education/Advice. POC use and percent days abstinent (PDA) at baseline, end-of-treatment and 3-months post treatment were examined using GLM Repeated Measures.

Results: Client adherence, retention and treatment satisfaction ratings were high. Therapists found the TTM intervention to be practical, feasible and easy to deliver in a substance abuse research clinic. During treatment increases in client use of the TTM experiential and behavioral POC were linked to reductions in cocaine use. Participants in both conditions significantly increased their POC use (p<.001) and reduced their cocaine use (p<.001). Treatments were moderated by baseline readiness to change. Participants with lower levels of baseline readiness to change their cocaine use had greater success in the TTM condition than in the Ed-Advice condition. Conversely, participants with higher levels of baseline readiness were more successful in the Ed-Advice condition.

Conclusions and Implications: Facilitating TTM experiential and behavioral POC use, and assigning participants to treatment groups based on their readiness to change may improve client outcomes. Tailoring group substance abuse treatment based on these results could have substantial positive impact on the delivery of treatment in community treatment programs.

Support: NIDA R01 DAO15453