Are changes in worry associated with treatment response in cognitive behavioral therapy for insomnia?

Little is known about why some patients respond to cognitive behavioral therapy for insomnia, whereas other patients do not. To understand differences in treatment response, there is a dire need to examine processes of change. The purpose was to investigate the long-term association between insomnia-related worry and outcomes following cognitive behavior therapy for insomnia.

Sixty patients with early insomnia (3-12 months duration) received group cognitive behavioral therapy for insomnia. At pretreatment and at a 1-year follow-up, the patients completed questionnaires indexing two domains of insomnia-related worry (sleeplessness and health), insomnia severity, anxiety, and depression as well as sleep diaries.

Decreases in the two worry domains were associated with improvements in all of the outcomes, except for sleep onset latency (SOL), at a medium to large level. Reductions in insomnia-related worry were associated with improvements in insomnia severity, wake after sleep onset (WASO), total sleep time (TST), and depression, but not in SOL or anxiety. While reductions in worry for sleeplessness were related to improvements in insomnia severity and TST, decreases in worry for health were associated with enhancements in WASO and depression.

The findings suggest that reductions in insomnia-related worry might be one process route in which cognitive behavioral therapy operates to improve insomnia symptomatology. The results are discussed in relation to theory, clinical implications, and future research.