Introduction: Sleep reactivity is the trait-like degree to which stress disrupts sleep, resulting in difficulty falling and staying asleep. Although previous studies have suggested that individuals who have high sleep reactivity may be resistant to cognitive-behavioral therapy for insomnia (CBT-I) effects, there have been no studies that have investigated this empirically. This study explored differential treatment responses in CBT-I based on sleep reactivity levels.
Material and method: Participants for this study were nineteen insomnia patients who met DSM-5 criteria for insomnia disorder. All participants received four weekly sessions of structured cognitive-behavioral therapy for insomnia (CBT-I). Individuals completed the Insomnia Severity Index (ISI), Korean version of Center for Epidemiologic Studies Depression Scale-Revised (K-CESD-R), Ford Insomnia Response to Stress Test (FIRST), Dysfunctional Beliefs and Attitudes about Sleep Scale-16 (DBAS-16), the Daily Inventory of Stressful Events (DISE) and a sleep diary. Participants were classified into two groups based on sleep reactivity level (high and low sleep reactivity).
Result: Following treatment, significant changes were found for ISI, K-CESD-R, DBAS-16 and FIRST scores, sleep onset latency, wake after sleep onset, sleep efficiency, number of awakenings, sleep quality and feeling refreshed upon awakening in both groups. Improvements in sleep efficiency was lower in the high sleep reactivity group compared to the low sleep reactivity group. No differences in ISI, K-CESD-R, DBAS-16 scores, and stress event frequency during the treatment duration were found between groups.
Conclusion: These findings suggest that sleep reactivity level may be an important factor that affects treatment outcome of CBT-I. Furthermore, the results may suggest that individual response to stress events are more important than the stressor itself.