Comparative efficacy and acceptability of psychosocial interventions for individuals with cocaine and amphetamine addiction: A systematic review and network meta-analysis

Abstract

Background: Clinical guidelines recommend psychosocial interventions for cocaine and/or amphetamine addiction as first-line treatment, but it is still unclear which intervention, if any, should be offered first. We aimed to estimate the comparative effectiveness of all available psychosocial interventions (alone or in combination) for the short- and long-term treatment of people with cocaine and/or amphetamine addiction.

Methods and findings: We searched published and unpublished randomised controlled trials (RCTs) comparing any structured psychosocial intervention against an active control or treatment as usual (TAU) for the treatment of cocaine and/or amphetamine addiction in adults. Primary outcome measures were efficacy (proportion of patients in abstinence, assessed by urinalysis) and acceptability (proportion of patients who dropped out due to any cause) at the end of treatment, but we also measured the acute (12 weeks) and long-term (longest duration of study follow-up) effects of the interventions and the longest duration of abstinence. Odds ratios (ORs) and standardised mean differences were estimated using pairwise and network meta-analysis with random effects. The risk of bias of the included studies was assessed with the Cochrane tool, and the strength of evidence with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. We followed the PRISMA for Network Meta-Analyses (PRISMA-NMA) guidelines, and the protocol was registered in PROSPERO (CRD 42017042900). We included 50 RCTs evaluating 12 psychosocial interventions or TAU in 6,942 participants. The strength of evidence ranged from high to very low. Compared to TAU, contingency management (CM) plus community reinforcement approach was the only intervention that increased the number of abstinent patients at the end of treatment (OR 2.84, 95% CI 1.24-6.51, P = 0.013), and also at 12 weeks (OR 7.60, 95% CI 2.03-28.37, P = 0.002) and at longest follow-up (OR 3.08, 95% CI 1.33-7.17, P = 0.008). At the end of treatment, CM plus community reinforcement approach had the highest number of statistically significant results in head-to-head comparisons, being more efficacious than cognitive behavioural therapy (CBT) (OR 2.44, 95% CI 1.02-5.88, P = 0.045), non-contingent rewards (OR 3.31, 95% CI 1.32-8.28, P = 0.010), and 12-step programme plus non-contingent rewards (OR 4.07, 95% CI 1.13-14.69, P = 0.031). CM plus community reinforcement approach was also associated with fewer dropouts than TAU, both at 12 weeks and the end of treatment (OR 3.92, P < 0.001, and 3.63, P < 0.001, respectively). At the longest follow-up, community reinforcement approach was more effective than non-contingent rewards, supportive-expressive psychodynamic therapy, TAU, and 12-step programme (OR ranging between 2.71, P = 0.026, and 4.58, P = 0.001), but the combination of community reinforcement approach with CM was superior also to CBT alone, CM alone, CM plus CBT, and 12-step programme plus non-contingent rewards (ORs between 2.50, P = 0.039, and 5.22, P < 0.001). The main limitations of our study were the quality of included studies and the lack of blinding, which may have increased the risk of performance bias. However, our analyses were based on objective outcomes, which are less likely to be biased.

Conclusions: To our knowledge, this network meta-analysis is the most comprehensive synthesis of data for psychosocial interventions in individuals with cocaine and/or amphetamine addiction. Our findings provide the best evidence base currently available to guide decision-making about psychosocial interventions for individuals with cocaine and/or amphetamine addiction and should inform patients, clinicians, and policy-makers.

Fig 1. Study selection.

The flowchart shows the records identified through database searching (black boxes), the records screened (blue boxes), the records excluded (red boxes), and the studies included (green boxes). CBT, cognitive behavioural therapy; RCT, randomised controlled trial.

Fig 2. Network of eligible comparisons for abstinence and dropout due to any cause at the end of treatment.

The figure plots the network of eligible direct comparisons for abstinence at the end of treatment (46 trials) (A) and dropout due to any cause (43 studies) (B). The width of the lines is proportional to the number of trials comparing every pair of treatments, and the size of every node is proportional to the number of randomised participants. The numbers above each connection relate to the numbers of trials and the numbers below each connection relate to the number of patients for each direct comparison. 12-step, 12-step programme; CBT, cognitive behavioural therapy; CM, contingency management; CRA, community reinforcement approach; MBT, meditation-based treatments; NCR, non-contingent rewards; SEPT, supportive-expressive psychodynamic therapy; TAU, treatment as usual.

Fig 3. Network meta-analysis of efficacy (yellow) and acceptability (blue) at the end of treatment.

Psychosocial treatments are reported in alphabetical order. Comparisons should be read from left to right. Abstinence and dropout estimates are located at the intersection between the column-defining and the row-defining treatment. For abstinence, ORs above 1 favour the column-defining treatment. For dropout, ORs above 1 favour the row-defining treatment. To obtain ORs for comparisons in the opposite direction, reciprocals should be taken. Significant results are in bold and underlined. CBT, cognitive behavioural therapy; CM, contingency management; CRA, community reinforcement approach; MBT, meditation-based therapies; NCR, non-contingent rewards; OR, odds ratio; SEPT, supportive-expressive psychodynamic therapy; TAU, treatment as usual; 12-step, 12-step programme.

Fig 4. Abstinence and dropout at different time-points for each psychosocial intervention versus treatment as usual.

Estimates are reported by ORs, where an OR above 1 favours the psychosocial intervention indicated on the left side over treatment as usual. For each intervention, efficacy outcomes are reported in the blue-shaded area, while acceptability outcomes are reported in the pink-shaded area. OR, odds ratio.