“…However, in our view, the homogenisation of diagnostic criteria across nosologies should definitely not lead us to give up further phenotyping ID. There is an urgent need for more research into insomnia subtypes with high clinical face validity (e.g., psychophysiological insomnia) or insomnia subtypes that are supported by high-quality research (e.g., insomnia with and without objective short sleep duration; see Nyhuis & Fernandez-Mendoza, 2023). To delineate and characterise these insomnia phenotypes, a data-driven approach seems to be the most promising (see e.g., Blanken et al, 2019).…”