Subtyping of Insomnia

Chronic insomnia is a widespread problem, affecting about ten percent of the adult population. Insomniacs form a heterogeneous group. As a consequence, a substantial part of the patients does not respond to the generic cognitive behavioral therapy (CBT-I). Large discrepancies between objective macrostructural characteristics of sleep evaluated by polysomnography and subjective reports of complaints have been found in insomnia patients. Therefore, increasing emphasis has been given to study microstructural characteristics of the EEG. Current research on EEG microstructure indicates that patients with insomnia have decreased sleep stability, possibly reflecting hyperarousal. Here, we aim to better understand underlying mechanisms of insomnia and heterogeneity in treatment response, assessing macro- and microstructural EEG parameters. Eventually, this could lead towards finding clinically relevant subtypes, personalizing treatment and even predicting individual treatment success.

Overall, 250 insomnia patients who are referred for CBT-I treatment to the Sleep Medicine Center Kempenhaeghe will take part in this study. Before the start of CBT-1, one night of ambulatory polysomnography (PSG) will be recorded at home. Cluster analysis will be used to detect groups of co-occurring macro- and microstructural EEG characteristics. We will focus on spectral power analysis, structural characteristics of REM-sleep, sleep protection mechanisms and (micro)arousals. We will evaluate these characteristics together, in order to study their relevance for phenotyping and their mutual relationships.

Chronic insomnia is a widespread problem, affecting about ten percent of the adult population. A generic and effective treatment for insomnia that targets hyperarousal is Cognitive Behavioural Therapy for insomnia (CBT-I). However, part of the insomnia patients does not respond to CBT-I and patients who do respond have variable outcomes. Scientific literature is increasingly becoming aware of the idea that insomnia is a general term for a number of subtypes consisting of different sleep complaints and having different causes. As a consequence, the effectiveness of (nonpharmacological)
treatment of a patient is likely to be strongly dependent of the patient’s individual characteristics. To date, no validated stratification method to subtype insomnia is available.



In this study we aim to better understand underlying mechanisms of insomnia and the heterogeneity in treatment response in a broad patient population, using cluster analysis as a tool for detecting subtypes. Subtypes will be detected with primary use of physiological parameters. Eventually, this study could lead towards finding clinically relevant subtypes, personalizing treatment and eventually even predicting if a non-pharmacological intervention for insomnia will be effective for an individual patient.

The study will be divided into two stages with a duration of approximately 15 and 21 months respectively.

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