Treatment response and non-response in CBT and Network Support for alcohol disorders: targeted mechanisms and common factors

Abstract

Aims: To determine whether mechanisms of drinking behavior change that are targeted by specific treatments mediate the effects of Packaged Cognitive Behavior Therapy (PCBT) and Network Support (NS) on abstinence rates throughout 27 months.

Design: Secondary analysis of data from two Network Support Project randomized clinical trials, in which participants were assigned to either a case management control treatment (control) or NS treatment in trial 1, or to PCBT or NS treatment in trial 2.

Setting: An out-patient substance abuse treatment site at a university medical center in the United States.

Participants: A total of 249 men and 154 women (n = 403) with alcohol use disorder.

Measurements: The primary outcome was membership in a treatment responder class determined by growth mixture modeling (GMM) of monthly proportion days abstinent (PDA) to 27 months. Key predictors of responder class membership included network change variables, and changes in coping scores and self-efficacy.

Findings: GMM analyses indicated that a three-class solution provided the best fit to the data: a treatment responder class comprising almost 55% of patients, a late relapsing class that showed post-treatment gains followed by a return to baseline drinking (12.7% of patients) and a non-responder class (32% of patients). Analyses indicated that treatment effects on responder class membership were moderated by baseline drinking (P < 0.001). PCBT effects were mediated by changes in coping scores (P < 0.05). NS treatment effects were also mediated by coping change, as well as by increases in self-efficacy and in number of abstinent friends (P < 0.05).

Conclusions: Long-term success in Packaged Cognitive Behavior Therapy and Network Support treatments for alcohol use disorder appears to be mediated by both general mechanisms (developing coping skills and self-efficacy) and treatment-targeted mechanisms (developing network strategies that emphasize social support and avoiding friends who drink).

Trial registration: ClinicalTrials.gov NCT00845208 NCT01129804.

Keywords: Alcohol treatment; Network Support; cognitive behavior therapy; common factors; coping skills; self-efficacy; treatment mechanisms.

Conflict of interest statement

Declarations of competing interest: None

© 2018 Society for the Study of Addiction.

Figures

Figure 1

PDA trajectory-based classes plotted derived from GMM analysis. The percentages shown refer to the percentage of patients who had membership in each of the classes. Dark lines show the mean PDA values for each trajectory for each time period. Gray broken lines show the estimated trajectories based on the GMM parameter estimates.