Treatment Adherence in Internet-Based CBT : The Effects of Presentation, Support and Motivation

Sammanfattning: Homework assignments that patient work with between sessions is a key component in both face-to-face and Internet-based Cognitive Behavior Therapy (CBT). However, adherence to assignments is often low and it is largely unclear what factors predict or affect treatment adherence, and in the end, treatment outcomes. The overall aim of this thesis was to investigate if treatment presentation and therapist support can affect adherence and treatment outcome in internet-based CBT, whether adherence can be predicted by motivation variables and to compare differences in face-to-face and online conditions in this regard.A randomized controlled trial with a brief online relaxation program for people with stress and anxiety symptoms was conducted (n = 162). Participants in the enhanced support conditions completed a larger proportion of the online treatment but adherence was not affected by enhanced treatment presentation (Study I). Participants reported reduced symptoms of stress and anxiety after the relaxation program but there were no significant additional effects of enhanced presentation or support (Study II). Participants who adhered to the prescribed assignments reported lower symptom levels at study end, regardless of treatment conditions. Adherence to the online treatment was predicted by subject factors such as treatment credibility prior to the treatment and intrinsic motivation during the treatment (Study III). To further elucidate how motivation may affect adherence, an experiment with a one-session psychotherapy model was subsequently conducted (n = 100). Participants who were randomized to the face-to-face condition reported higher motivation for the assignment and completed significantly more of the homework compared to participants in the online condition (Study IV). Self-reported intrinsic motivation could predict adherence in both conditions while new motivational variables were identified specifically for the online condition.The results from these studies confirm that adherence to assignments in Internet-based CBT is difficult to affect with treatment features but can be predicted early in treatment by subject factors such as treatment credibility and motivation. How such motivational variables can be affected to improve treatments is still unclear.