Predicting Outcome in Internet-Based Cognitive Behaviour Therapy for Major Depression: A Large Cohort Study of Adult Patients in Routine Psychiatric Care

Background Although the effectiveness of therapist-guided internet-based cognitive behaviour therapy (ICBT) for treating depression has been well documented, knowledge of outcome predictors and risk factors associated with lower treatment response is limited, especially when the treatment has been conducted within a naturalistic clinical setting. Identification of such factors is important for clinicians when making treatment recommendations. Methods Data from a large cohort (N = 1738) of adult outpatients having been treated with ICBT for depression at an outpatient psychiatric clinic were analysed. A multilevel modelling approach was used to identify patient and treatment variables associated with the speed of recovery during treatment using weekly measurements of the Montgomery Asberg Depression Rating Scale Self-Rated (MADRS-S). Outcomes Adhering to the treatment, perceiving it as credible and working full-time emerged as predictors of a faster pace of recovery and were also associated with a lower level of depression at the end of treatment. Higher pre-treatment depression and sleep problems were associated with a greater improvement rate, but predicted higher depression after treatment. Having a history of psychotropic medication was associated with both slower improvement and higher post-treatment depression. Conclusion Perceived credibility of ICBT is a strong predictor of treatment response. Assessing patient beliefs and expectations may be a useful aid for clinicians when identifying those who are more or less likely to benefit from ICBT. Helping patients improve expectations prior to treatment may be an important goal for clinicians during the initial assessment phase.