Mindfulness Treatment for Substance Misuse: A Systematic Review and Meta-Analysis

Background:High rates of relapse following substance misuse treatment highlight an urgent need for effective therapies. Mindfulness treatment is considered a promising approach for substance misuse. Although the number of empirical studies investigating effects of mindfulness treatment for substance misuse has increased dramatically in recent years, no prior review has examined findings of mindfulness studies published between 2012 and 2015 (Chiesa & Alessandro, 2014; Katz & Toner, 2013; Zgierska et al., 2009). Thus, this systematic review examined substantive findings of studies evaluating mindfulness treatment for substance misuse published by 2015. The review also includes meta-analyses of randomized controlled trial (RCT) studies of mindfulness treatment for substance misuse.

Methods: Comprehensive searches in PubMed, PsycInfo, and Web of Science were conducted in May and December, 2015 using search phrases including “substance *use,” and “mindfulness.” Forty-nine studies were identified for the systematic-review. Only RCTs were included in the meta-analyses. Standardized mean differences in posttreatment values of outcome variables between mindfulness and comparison conditions were used to estimate effect sizes of mindfulness treatment on severity of substance misuse, intensity of craving, stress level, and level of mindfulness. Odds ratios were used to compute effect sizes for studies reporting point-prevalence of abstinence rates. Cohen’s d/odds ratios were computed for each study as appropriate and pooled, and then a synthesized effect size was computed for each treatment outcome using the Stata program metan. Considering that the true value of the estimated effect size for outcome variables might vary across different trials and samples, a random effects model was used.

Results: The systematic review provides detailed information on substantive findings and methodological characteristics of each reviewed study. A majority of studies showed that mindfulness treatment was effective in reducing substance misuse (e.g., alcohol and drug misuse and cigarette smoking), and increasing psychosocial well-being (e.g., reducing psychiatric distress and increasing positive coping) at posttreatment and follow-up assessments. Meta-analytic results revealed a significant small effect of mindfulness treatment on reducing substance misuse (N = 6, d = -.33, 95% CI [-.88, -.14]), a significant medium effect on reducing craving for substances (N = 7, d = -.63, 95% CI [-1.17, -.08]), a significant large effect on reducing stress (N = 5, d = -1.12, 95% CI [-2.24, -.01]), and a medium effect on increasing mindfulness (N = 8, d= .61, 95% CI [-.02, 1.24]) at posttreatment compared to a comparison condition. Moreover, the synthesized odds ratio of mindfulness treatment on point-prevalence abstinence of cigarette smoking compared to an alternative treatment across 4 RCTs was 1.76 (95% CI [.98, 3.15]).

Conclusion and Implications: This review supports a positive effect of mindfulness treatment on substance misuse. Meta-analytic results revealed significant small-to-large effects of mindfulness treatment vis-a-vis reducing severity of substance misuse, intensity of craving for psychoactive substances, and stress levels, and in terms of increasing abstinence from cigarette smoking at posttreatment compared to alternative treatments. Findings from this systematic review and meta-analysis contribute to the evidence base for mindfulness treatment for substance misuse problems in diverse populations.