Comorbid insomnia represents a frequent health problem in patients with severe mental disorders, and cognitive behavioral therapy for insomnia (CBT-I) has been identified as the first line treatment. However, CBT-I has not sufficiently been implemented in acute psychiatry settings. Rather, patients are often overtreated with benzodiazepines or benzodiazepine receptor agonists, related to adverse effects and the risk of tolerance and dependency. This work aims to empower patients with severe mental disorders to take care of their own sleep health based on a pragmatic behavioral treatment program (Become your own SLEEPexpert). Implementation research strategies in collaboration with patients and health care providers were used to adaptat CBT-I components to the needs of psychiatric inpatients. Evidence for feasibility in an acute hospital setting and preliminary evidence for efficacy has been shown. ln the proposed project, the investigators aim to compare treatment as usual (TAU) + SLEEPexpert to TAU + sleep monitoring in a pilot randomized controlled trial. The objective is to target sleep to improve mental health and to investigate the efficacy of the SLEEPexpert programme for the improvement of sleep and mental health. Given the high burden of comorbid insomnia in psychiatry, the investigators believe that the presented work is of interest to basic scientists and clinicians and, potentially, of heightened public health relevance.