Cognitive Remediation as an Adjunct Treatment for Substance Use Disorders: A Systematic Review

Substance use disorders are associated with diverse neuropsychological impairments, with deficits in memory and executive functioning commonly observed. Cognitive remediation has been shown to be effective in other populations with cognitive impairments in these domains, including those with psychiatric disorders and acquired brain injuries, and it has been hypothesised to be similarly effective for those in treatment for substance use disorders. We aimed to systematically review the evidence for cognitive remediation interventions administered as an adjunct treatment to substance use rehabilitation. Studies were included if participants were receiving substance use treatment, if improving cognitive functioning was the main focus of the intervention and if they used an experimental design with a control condition receiving treatment-as-usual or an active control intervention. Two independent reviewers agreed on the final selection of 32 studies, encompassing cognitive remediation for working memory, memory, executive functioning and general cognition. Significant differences between intervention and control groups for cognitive test results and treatment outcomes were extracted and compared across treatment approaches. The review found considerable heterogeneity across studies, including in the types of interventions, the nature of participants and the outcome measures used. Further, a lack of quality studies with sufficient power meant that limited conclusions could be drawn, highlighting a need for further replication and research. However, findings indicate that cognitive remediation remains a promising potential avenue for improving cognition and treatment outcomes for those in treatment for substance use disorders. Protocol submitted prospectively to PROSPERO 30.09.2019, CRD42020150978.