Mindfulness-Based Intervention Effects on Substance Use and Relapse Among Women in Residential Treatment: A Randomized Controlled Trial With 8.5-Month Follow-Up Period From the Moment-by-Moment in Women's Recovery Project

Objective We tested the efficacy of Moment-by-Moment in Women's Recovery (MMWR), a mindfulness training program adapted for ethnoculturally diverse women with complex social and clinical histories in residential treatment for substance use disorder, on substance use and relapse outcomes. Methods Participants were randomized to MMWR (n = 100; 60% Hispanic/Latina, 18% non-Hispanic Black) or the attention control condition, Neurobiology of Addiction (n = 100; 56% Hispanic/Latina, 21% non-Hispanic Black). Substance use outcomes (days until first use, days of use, and relapse status: abstained, lapsed, relapsed) were obtained from interviewer-assisted timeline followback for an 8.5-month follow-up period spanning the intervention start through the 6-week intervention period and 7 months after the intervention ended. Results An intent-to-treat survival analyses showed that time delay to first marijuana use favored MMWR (hazard ratio = 0.44, 95% confidence interval = 0.20-0.98, p = .049) with a medium-to-large effect size. In negative binomial hurdle models, the MMWR group showed fewer days of marijuana use at 3.5 months (B = -1.71, SE = 0.79, incidence rate ratio = 0.18, p = .030) and a trend at 7 months after the intervention (B = -0.90, standard error = 0.55, incidence rate ratio = 0.41, p = .10). For marijuana, mindfulness practice time during the intervention predicted time delay to first use (B = 0.28, p = .006) and total abstinence days (B = 0.34, p = .002) across the 7 months after MMWR. No other substance use outcomes showed differential response to MMWR relative to controls. Only in MMWR, number of study intervention sessions attended (dose) correlated with a greater length of time to alcohol intoxication (r = .48, p < .001), fewer days of alcohol intoxication (r = -.24, p = .020), and greater improvement in mindfulness skills (r = .61, p < .01). Conclusions MMWR added to an ongoing intensive residential treatment program serving vulnerable women is protective against marijuana use but no other substance use outcomes. Mindfulness practice time predicted a delay in time to first marijuana use. MMWR class attendance, an indicator of intervention dose, appears protective of alcohol intoxication at follow-up; thus, extended MMWR exposure might be useful.