Impact of Comorbid Psychological Distress on Stimulant Use Disorder Treatment Outcomes

Psychological distress is common among individuals with stimulant use disorder (StUD) and may affect treatment outcomes, with potential differences in men and women. We examined the impact of comorbid psychological distress on StUD treatment outcomes across behavioral interventions, with a focus on differences by sex.

Data were pooled from 4 randomized controlled trials of behavioral interventions (eg, motivational interviewing, 12-step, and smoking-cessation) for StUD (n = 1858) from the National Institute on Drug Abuse Data Share. Psychological distress was assessed using the Addiction Severity Index-psychiatric problems subscale (≥0.246 cutoff). Outcomes included (a) any reduction in stimulant use frequency from baseline to the end of trial, (b) stimulant-positive urine test, and (c) other drug-positive urine tests at the end of trial. We used individual participant data meta-analysis with regression models, adjusting for sociodemographic factors, treatment arms and trial duration, and clustering by trials. We used inverse probability weighting to address missing data. Analyses were conducted on the full sample and stratified by sex.

Overall, 57.1% of women and 38.7% of men experienced psychological distress. Among men, psychological distress was associated with decreased odds of reducing stimulant use (adjusted odds ratio [aOR] = 0.70, 95% confidence interval [CI] = 0.49, 0.99), and increased odds of having a stimulant-positive urine test (aOR = 1.23, 95% CI = 1.03, 1.47). Among women, distress was not significantly associated with reduced stimulant use or with having a stimulant-positive urine test. However, psychological distress moderated the treatment effect: women with psychological distress who received behavioral interventions were more likely to reduce stimulant use than those without psychological distress.

Psychological distress was associated with poorer treatment outcomes for men but appeared to enhance treatment response for women. Screening and addressing psychological distress may improve StUD treatment. Sex differences highlight the need for sex-specific approaches to managing psychological distress in StUDs.