Understanding and Enhancing Adherence to Sleep Restriction Therapy

• Applicant: Laura Simon
• Subject Area: Personality Psychology, Clinical and Medical Psychology, Methodology ; Clinical Psychiatry, Psychotherapy, Child and Adolescent Psychiatry
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 577775488

Insomnia is among the most common sleep disorders, affecting approximately 12% of the general population. An evidence-based treatment option for insomnia is sleep restriction therapy (SRT). In this approach, the time spent in bed, referred to as the sleep window, is deliberately reduced to better match the individual’s self-reported sleep duration. It is assumed that consistent adherence to this sleep window is crucial for treatment success. Despite this theoretical assumption, only a few studies have empirically demonstrated a clear relationship between adherence and treatment outcomes. One possible explanation for these inconsistent findings is that adherence has been defined and measured in varying ways across studies. The aim of this research project is therefore to deepen the understanding of the role of adherence in the effectiveness of SRT. The central question is whether a relationship exists between adherence and treatment outcomes, and if so, which measure of adherence best predicts treatment outcomes and whether the timing of adherence during therapy influences this relationship. To address this, data from previously conducted studies will be pooled and analyzed in an individual patient data meta-analysis in the first work package. Various adherence measures derived from sleep diary data will be compared to identify the measure most strongly associated with improvements in insomnia symptoms by the end of treatment. Furthermore, the project investigates whether targeted enhancement of adherence can be a route for optimizing SRT. The second work package focuses on the development of a flexible, adaptive SRT protocol that provides individualized support for participants during treatment if adherence declines. The study will use continuous monitoring of adherence to enable early detection of declines, which can then be addressed through tailored feedback or support interventions. The feasibility of this approach will be evaluated in a pilot study using a single-case experimental design. In the long term, the project aims to sustainably improve the effectiveness of sleep restriction therapy through a better understanding and targeted promotion of adherence.

• DFG Programme: Fellowship
• International Connection: Netherlands, United Kingdom
• Hosts: Dr. Tessa Blanken; Professor Simon Kyle, Ph.D.; Dr. Jaap Lancee