Mediators of cognitive-behavioral therapy for insomnia: A review of randomized controlled trials and secondary analysis studies

• Published in: Clinical psychology review 2012-11, Vol.32 (7), p.664-675
• Main Authors: Schwartz, Danielle R., Carney, Colleen E.
• Format: Article
• Language: English
• Subjects: Cognitive Therapy - methods; Cognitive-behavioral therapy; Humans; Insomnia; Mediators; Randomized controlled trials; Randomized Controlled Trials as Topic; Secondary analysis studies; Sleep; Sleep Initiation and Maintenance Disorders - psychology; Sleep Initiation and Maintenance Disorders - therapy; Treatment Outcome
• ISSN: 0272-7358; 1873-7811
• DOI: 10.1016/j.cpr.2012.06.006

The examination of treatment mechanisms in randomized controlled trials (RCTs) has considerable implications for research and clinical practice. Insomnia is a highly prevalent and distressing disorder, associated with many adverse outcomes. Although extensive work has focused on the cognitive-behavioral treatment of insomnia (CBT-I), few studies have directly examined the mechanisms of this intervention. CBT-I is a short-term, multi-component treatment that has demonstrated strong efficacy in treating insomnia. The purpose of the present study is: (a) to investigate if CBT-I works in accordance with its proposed mechanisms, and (b) to evaluate how the field is progressing in its understanding of these processes. This study comprehensively reviewed CBT-I RCTs for their inclusion of mediator variables. Secondary analysis studies were also surveyed for relevant mediator variables. Results demonstrated that 21 RCTs (39% of the total RCTs) and 11 secondary analysis studies examined at least one of the proposed mediators. Results of this review highlight that, although CBT-I appears to be targeting the hypothesized sleep processes, more research is needed to better understand whether CBT-I works in accordance with its theorized mechanisms. Inclusion of mediational analyses in future RCTs and secondary analysis studies would allow for further refinement of CBT-I and improved treatment outcomes. ► This study reviewed mediators of cognitive-behavioral therapy for insomnia. ► Randomized controlled trials and secondary analysis studies were investigated. ► 21 RCTs (39% of total) and 11 secondary analysis studies included mediator variables. ► Cognitive-behavioral therapy of insomnia appears to target proposed sleep processes. ► Future mediational analyses would allow for further refinement of treatment.