Adaptive actions and treatment outcomes in transdiagnostic internet-delivered cognitive behaviour therapy for chronic health conditions.

Transdiagnostic internet-delivered cognitive behavioural therapy (ICBT) has demonstrated effectiveness for improving a range of outcomes for individuals living with diverse chronic health conditions. However, the behavioural processes that contribute to these outcomes remain unclear. This study examined whether participation in a 5-lesson transdiagnostic ICBT program for chronic health conditions was associated with changes in adaptive actions (i.e., Healthy Thinking, Meaningful Activities, Goals and Plans, Healthy Habits, and Social Connections) and whether these changes were maintained at follow-up. We also explored whether changes in adaptive actions were associated with changes on measures of depression, anxiety, pain intensity, and pain interference. Adults (N = 121) received a transdiagnostic ICBT program for chronic health conditions in a routine online care setting. Adaptive actions were assessed with the Things You Do Questionnaire-15 Item (TYDQ-15). GEE analyses indicated that the TYDQ-15 total and domain scores improved significantly from pre- to post-treatment and were maintained at follow-up. Effect sizes were small to moderate. Hierarchical linear regression models indicated a significant association between adaptive behaviours and clinical outcomes on the PHQ-9, GAD-7, and BPI-Interference. The findings highlight the potential value of encouraging adaptive actions early in treatment and underscore the need for further research to identify actions that may contribute to improvements in depression, anxiety, and related outcomes.