Network Intervention Analyses of cognitive therapy and behavior therapy for insomnia: Symptom specific effects and process measures.

Cognitive therapy (CT) and behavior therapy (BT) are both effective for insomnia. In this study we applied Network Intervention Analysis to investigate specific effects of CT and BT on outcomes and process measures. The analysis was based on a randomized controlled trial comparing CT (n = 65), BT (n = 63) and cognitive behavioral therapy for insomnia (n = 60; not included in this study). In the first networks, the separate items of the Insomnia Severity Index and sleep efficiency were included. In the second networks, the pre-specified process measures for BT and CT, sleep efficiency, and the sum-score of the Insomnia Severity Index were included. At the different time points, we found CT-effects on worry, impaired quality of life, dysfunctional beliefs, and monitoring sleep-related threats, and BT-effects on sleep efficiency, difficulty maintaining sleep, early morning awakening, time in bed, sleep incompatible behaviors and bed- and rise time variability. These observed effects of CT and BT were consistent with their respective theoretical underpinnings. This study provided new information on the mechanisms of change in CT and BT. In the future, this may guide us to the most effective treatment modules or even subsets of interventions.