Effects of mindfulness-based interventions on depressive symptoms in patients with substance use disorders: a systematic review and meta-analysis

Abstract Objective We examined the effects of mindfulness-based interventions (MBIs) on depressive symptoms in patients with substance use disorders (SUDs) and explored the moderating effects of participant, method, and intervention characteristics.

Methods: We systematically searched 8 databases from their inception till November 2021. The inclusion criteria were primary studies evaluating MBIs in patients with SUDs with depression measured as an outcome, those including a control group, and those written in English. We used a random-effects model to compute effect sizes (ESs) using Hedges’ g, a forest plot, and Q and I 2 statistics as measures of heterogeneity; we also examined moderator analyses.

Results: Nineteen studies included 1352 participants (age: 38.6 ± 7.0 years). Overall, MBIs showed significantly improved depression ( g = 0.67, 95% confidence interval [CI]: 0.29, 1.05, I 2 = 89%) compared to controls. With regard to moderators, providing MBIs as an individual plus group intervention had a greater effect ( g = 2.13) on reducing depressive symptoms than providing MBIs as a group intervention ( g = 0.64) or an individual intervention only ( g = 0.33, P = 0.034). Using concealed allocation tended to reduce depressive symptoms ( g = 1.22) as compared to not using concealed allocation ( g = 0.48, P = 0.086). No other quality indicators were demonstrated to have a moderating influence on the value of the ES.

Conclusions: MBIs improved depressive symptoms in patients with SUDs. MBIs might be used as an adjunctive or alternative to conventional treatment for depressed patients with SUDs.