Interventions for drug-using offenders with co-occurring mental health problems

Background This review represents one from a family of three reviews focusing on interventions for drug-using offenders. Many people under the care of the criminal justice system have co-occurring mental health problems and drug misuse problems; it is important to identify the most effective treatments for this vulnerable population. Objectives To assess the effectiveness of interventions for drug-using offenders with co-occurring mental health problems in reducing criminal activity or drug use, or both. This review addresses the following questions. Does any treatment for drug-using offenders with co-occurring mental health problems reduce drug use? Does any treatment for drug-using offenders with co-occurring mental health problems reduce criminal activity? Does the treatment setting (court, community, prison/secure establishment) affect intervention outcome(s)? Does the type of treatment affect treatment outcome(s)? Search methods We searched 12 databases up to February 2019 and checked the reference lists of included studies. We contacted experts in the field for further information. Selection criteria We included randomised controlled trials designed to prevent relapse of drug use and/or criminal activity among drug-using offenders with co-occurring mental health problems. Data collection and analysis We used standard methodological procedures as expected by Cochrane. Main results We included 13 studies with a total of 2606 participants. Interventions were delivered in prison (eight studies; 61%), in court (two studies; 15%), in the community (two studies; 15%), or at a medium secure hospital (one study; 8%). Main sources of bias were unclear risk of selection bias and high risk of detection bias. Four studies compared a therapeutic community intervention versus (1) treatment as usual (two studies; 266 participants), providing moderate-certainty evidence that participants who received the intervention were less likely to be involved in subsequent criminal activity (risk ratio (RR) 0.67, 95% confidence interval (CI) 0.53 to 0.84) or returned to prison (RR 0.40, 95% C10.24 to 0.67); (2) a cognitive-behavioural therapy (one study; 314 participants), reporting no significant reduction in self-reported drug use (RR 0.78, 95% CI 0.46 to 1.32), re-arrest for any type of crime (RR 0.69, 95% C10.44 to 1.09), criminal activity (RR 0.74, 95% CI 0.52 to 1.05), or drug-related crime (RR 0.87, 95% C10.56 to 1.36), yielding low-certainty evidence; and (3) a waiting list control (one study; 478 participants), showing a significant reduction in return to prison for those people engaging in the therapeutic community (RR 0.60, 95% CI 0.46 to 0.79), providing moderate-certainty evidence. Two studies reported on the use of multi-systemic therapy involving juveniles and families versus treatment as usual and adolescent substance abuse therapy. In comparing treatment as usual, researchers found no significant reduction up to seven months in drug dependence on the Drug Use Disorders Identification Test (DUDIT) score (MD -0.22, 95% CI -2.51 to 2.07) nor in arrests (RR 0.97, 95% CI 0.70 to 1.36), providing low-certainty evidence (156 participants). In comparison to an adolescent substance abuse therapy, one study (112 participants) found significant reduction in re-arrests up to 24 months (MD 0.24, 95% CI 0.76 to 0.28), based on low-certainty evidence. One study (38 participants) reported on the use of interpersonal psychotherapy in comparison to a psychoeducational intervention. Investigators found no significant reduction in self-reported drug use at three months (RR 0.67, 95% CI 0.30 to 1.50), providing very low-certainty evidence. The final study (29 participants) compared legal defence service and wrap-around social work services versus legal defence service only and found no significant reductions in the number of new offences committed at 12 months (RR 0.64, 95% CI 0.07 to 6.01), yielding very low-certainty evidence. Authors' conclusions Therapeutic community interventions and mental health treatment courts may help people to reduce subsequent drug use and/or criminal activity. For other interventions such as interpersonal psychotherapy, multi-systemic therapy, legal defence wrap-around services, and motivational interviewing, the evidence is more uncertain. Studies showed a high degree of variation, warranting a degree of caution in interpreting the magnitude of effect and the direction of benefit for treatment outcomes.