Individually tailored internet-based treatment for depression and comorbid conditions

Abstract

Background: Depression is a large societal problem. People suffering from depression are heterogeneous and have a high degree of comorbid conditions. Pharmacological treatment is widespread, but not effective for all sufferers, and patients often have a preference for psychological treatment. There are effective psychological treatment alternatives, but access to treatment is low. Individually tailored internet-based treatment has the ability to target several conditions within the same treatment. It has shown promising effects on depression and anxiety but needs to be further evaluated against other interventions. The effects of specific treatment components also need to be explored.

Aims: The aims of this thesis were to evaluate the effects and cost-effectiveness of individually tailored internet-based treatment compared to other treatment alternatives, to compare its effects to disorder-specific benchmark treatments, and to explore if compliance to treatment components for specific conditions predict reductions in the targeted symptoms.

Methods: Study I-IV were based on the randomized trial REGASSA (n = 946) where an individually tailored internet-based treatment (TAIL) were compared to structured physical exercise (PE) and to treatment as usual in primary care (TAU). In Study I, the effects of TAIL and PE on depression symptoms were evaluated against TAU. Study II evaluated the cost-effectiveness of TAIL and PE against TAU. In Study III, TAIL was compared to similar, but disorder-specific, benchmark treatments for depression (n = 2358), panic disorder (n = 1176) and social anxiety disorder (n = 1335). In Study IV, the participants’ compliance to the different specific components in the TAIL-intervention were rated, and related to symptom reductions.

Results: The effects of TAIL on depression symptoms were large (g = 1.47, 95% CI 1.29-1.66), and there were significantly larger reductions in depression symptoms than in the TAU-group. There were no significant differences in effects on depression symptoms between TAIL and PE. TAIL and PE had 90 and 76 % probabilities respectively, of being cost-effective compared to TAU, given standard health care provider willingness to pay-thresholds. The effects of TAIL on depression symptoms were non-inferior to disorder-specific internet-based treatment. The effects of TAIL on panic or social anxiety symptoms however, could not be concluded to be non-inferior to disorder-specific treatment. Overall compliance with TAIL was strongly related to symptom reductions in depression, panic, social anxiety, stress and insomnia, weakly related to reductions in worry, but not related to reductions in pain symptoms. Compliance to specific components for social anxiety was related to reductions in specific social anxiety symptoms. Compliance to specific components for stress and insomnia were particularly important since they were related to both specific symptom reductions and reductions of depressive symptoms.

Conclusions: The results in this thesis support that individually tailored internet-based treatment is an effective and cost-effective treatment alternative to be considered for implementation. It is as effective as the disorder-specific internet-based treatments for depression already used in routine care, but more comparisons are needed to conclude if it is as effective as disorder-specific anxiety treatments. Since specific treatment components for stress and insomnia were important for both specific and depressive symptom reductions, it is probable that individual tailoring for these conditions is worthwhile in the treatment of depression.