Understanding delayed sleep-wake phase disorder (DSWPD): Mechanisms, comorbidities, and evolving approaches to diagnosis and treatment

Gorica Micic; Amy C Reynolds; Andrew J K Phillips; Phyllis Zee; Cele Richardson; Helen J Burgess; Leon Lack; Peter Catcheside; Cathy A Goldstein; Hannah Scott; Sean Cain; Robert Adams; Nicole Lovato

doi:10.1016/j.smrv.2026.102240

Understanding delayed sleep-wake phase disorder (DSWPD): Mechanisms, comorbidities, and evolving approaches to diagnosis and treatment

Sleep Med Rev. 2026 Apr:86:102240. doi: 10.1016/j.smrv.2026.102240. Epub 2026 Jan 30.

Authors

Affiliations

¹ Flinders University, College of Medicine and Public Health, Flinders Health and Medical Research Institute (FHMRI): Sleep Health, Bedford Park, South Australia, Australia; AISH Sleep Health Clinics, Flinders University, Bedford Park, South Australia, Australia. Electronic address: gorica.micic@flinders.edu.au.
² Flinders University, College of Medicine and Public Health, Flinders Health and Medical Research Institute (FHMRI): Sleep Health, Bedford Park, South Australia, Australia; AISH Sleep Health Clinics, Flinders University, Bedford Park, South Australia, Australia.
³ Flinders University, College of Medicine and Public Health, Flinders Health and Medical Research Institute (FHMRI): Sleep Health, Bedford Park, South Australia, Australia.
⁴ Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
⁵ School of Psychological Science and Centre for Sleep Science, University of Western Australia, Perth, Western Australia, Australia.
⁶ Sleep and Circadian Research Laboratory, Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.
⁷ AISH Sleep Health Clinics, Flinders University, Bedford Park, South Australia, Australia; Flinders University, College of Education, Psychology, and Social Work, South Australia, Australia.
⁸ Sleep Disorders Center, University of Michigan, Ann Arbor, MI, USA.

PMID: 41679168
DOI: 10.1016/j.smrv.2026.102240

Abstract

Background: Delayed Sleep-Wake Phase Disorder (DSWPD) is a circadian rhythm disorder marked by a consistent and distressing delay in sleep timing relative to societal norms. While traditionally viewed as a circadian phase disorder, growing evidence shows psychological, behavioural, and physical health factors interact with circadian biology to influence onset, maintenance, and outcomes.

Purpose: of review: This review synthesises recent literature on DSWPD's multifactorial nature, focusing on aetiology, nosology, comorbidities, and treatment. It highlights emerging evidence supporting a multidimensional diagnostic approach and personalised, multimodal management.

Recent findings: Some individuals with DSWPD exhibit a significantly delayed circadian phase, while others show normal circadian timing but persistently delayed sleep behaviour. A spectrum approach or subtyping into circadian and behavioural variants has been proposed. Comorbidities with psychiatric conditions including depression, anxiety, ADHD and autism are common and may affect treatment response. Chronobiotic treatments remain core, but cognitive-behavioural and psychotherapeutic interventions are increasingly essential, especially in non-circadian or comorbid cases. Advances in wearable technology and circadian modelling offer promising tools for diagnosis, monitoring, intervention.

Summary: DSWPD is heterogeneous and requires an integrative, individualised approach considering circadian biology, behaviour and psychiatric comorbidities. A multidimensional diagnostic and treatment model could improve outcomes and functioning.

Keywords: Circadian modelling; Circadian rhythm sleep-wake disorders; Circadian subtypes; Clinical management; Delayed sleep-wake phase disorder; Mental health.

Publication types

Review

MeSH terms

Circadian Rhythm / physiology
Comorbidity
Humans
Sleep Disorders, Circadian Rhythm* / diagnosis
Sleep Disorders, Circadian Rhythm* / epidemiology
Sleep Disorders, Circadian Rhythm* / physiopathology
Sleep Disorders, Circadian Rhythm* / therapy