12-Step Affiliation and Attendance Following Treatment for Comorbid Substance Dependence and Depression: A Latent Growth Curve Mediation Model

ABSTRACT

  Among substance-dependent individuals, comorbid major depressive disorder (MDD) is associated with greater severity and poorer treatment outcomes, but little research has examined mediators of posttreatment substance use outcomes within this population. Using latent growth curve models, the authors tested relationships between individual rates of change in 12-step involvement and substance use, utilizing posttreatment follow-up data from a trial of group Twelve-Step Facilitation (TSF) and integrated cognitive-behavioral therapy (ICBT) for veterans with substance dependence and MDD. Although TSF patients were higher on 12-step affiliation and meeting attendance at end-of-treatment as compared with ICBT, they also experienced significantly greater reductions in these variables during the year following treatment, ending at similar levels as ICBT. Veterans in TSF also had significantly greater increases in drinking frequency during follow-up, and this group difference was mediated by their greater reductions in 12-step affiliation and meeting attendance. Patients with comorbid depression appear to have difficulty sustaining high levels of 12-step involvement after the conclusion of formal 12-step interventions, which predicts poorer drinking outcomes over time. Modifications to TSF and other formal 12-step protocols or continued therapeutic contact may be necessary to sustain 12-step involvement and reduced drinking for patients with substance dependence and MDD.

Keywords:

• Comorbidity
• mediation
• 12-step involvement

Acknowledgments

This research was funded by Department of Veterans Affairs, Veterans Health Administration, Office of Research and Development, Clinical Sciences Research & Development Merit Review Awards to Dr. Sandra A. Brown and Dr. Susan R. Tate, and by National Institute on Drug Abuse fellowship grant (F31DA030861) awarded to Matthew J. Worley.Clinical trials registration: Clinicaltrials.gov identifiers NCT00108407 and NCT00018655.