0454 Predictors of CBT-I Adherence in Pregnant Women: The Role of Pregnancy-Related Stress and Treatment Format

Abstract Introduction Pregnant women represent a unique population with vulnerabilities to mood disturbances, insomnia and stress. Past research has shown that more severe mood and insomnia symptoms at baseline predicted poorer treatment adherence in cognitive behavioral therapy for insomnia (CBT-I). However, research on treatment adherence in pregnant women remains limited. This study aimed to examine whether mood, insomnia, stress and treatment format could predict adherence in pregnant women receiving CBT-I. Methods 73 pregnant women with DSM-5 insomnia disorder and ISI score ≥ 8 participated in a 6-session CBT-I program delivered either in a group-based (age: 34.9± 3.23 years, gestation week: 25.7 ± 4.53) or App (age: 34.3 ± 3.23 years, mean gestation week: 25.7 ±5.58) format. They completed questionnaires assessing perinatal stress (Pregnancy Stress Rating Scale, PSRS), perinatal depression (Edinburgh Postnatal Depression Scale, EPDS), and insomnia severity (Insomnia Severity Index, ISI) at baseline. Adherence was evaluated using the Treatment Components Adherence Scale. Linear regression models were conducted for each adherence outcome, with EPDS, ISI, PSRS as independent variables and age as a covariate. Results Improvement in insomnia symptoms was significantly associated with overall treatment adherence, r(71)=0.328, p=0.002. The linear regression model for cognitive adherence showed a significant overall fit (R = 0.401, R2 = .161, F(5,67) = 2.56, p = 0.035). Higher pregnancy-related stress was associated with poorer adherence to cognitive elements (β = −0.01, p = 0.013); compared to App, group CBT-I was associated with better cognitive adherence (β=0.39, p=0.037). The model for behavioural adherence was not statistically significant (R = 0.319, R2 = 0.102, F(5,67) = 1.52, p = 0.195). Conclusion The findings suggest that both the format of therapy and pregnancy-related stress may influence adherence to the cognitive elements of CBT-I in pregnant women. Elevated pregnancy-specific stress may amplify worries that hinder engagement in sleep-related cognitive restructuring. Future research may explore the potential effects of tailoring sleep intervention to address pregnancy-specific stress and whether such adaptations could enhance treatment adherence and improve clinical outcomes. Support (if any) This work was funded by the Health and Medical Research Fund (HMRF, Ref. 20212091), the Food and Health Bureau, Hong Kong SAR, China.