Patients who suffer from depression in combination with insomnia are known to have worse treatment outcomes and lower quality of life compared to depressed patients without co-occurring insomnia. This leads to higher productivity losses and mental healthcare utilization. In regular care, patients often receive medication to treat insomnia, while first choice treatment is Cognitive Behavioral Therapy (CBT) for insomnia. This is often not provided because it is time consuming and treatment is focused on depression alone. Online CBT may be a solution to provide this therapy In a cost-effective format.

The aim of this study is to test the (cost)-effectiveness of online Cognitive Behavioral Therapy for Insomnia (CBT-I, iSleep) in combination with regular depression treatment in organisations for mental health care. Participants have to meet the criteria major depressive disorder and insomnia according to DSM-V. A multi-site randomized controlled trial is being conducted (n=114). Results of the study will be ready in 2026.