A new subtype of depression, 'circadian depression,' linked to biological clock disruptions, affects 23% of patients and responds poorly to traditional antidepressants.
New depression subtype identified
An Australian study has identified a new subtype of depression, termed "circadian depression," which is associated with disruptions in the body's biological clock. This form of depression, affecting approximately 23% of participants in the study, is linked to more complex symptoms and a less favorable response to classical antidepressants, according to researchers from the University of Sydney.Study details and findings
The findings, published in the British Journal of Psychiatry on October 21, 2026, were based on clinical and genetic data from 11,380 individuals suffering from severe, recurrent, or persistent depression. The study highlights that individuals with circadian depression often experience symptoms such as sleeping late, waking up exhausted, and continuing to feel unwell despite antidepressant treatment.Researcher insights
Emiliana Tonini, the first author of the study, stated that the research identified circadian depression as a new subtype affecting about a quarter of the participants. She emphasized that depression is not a uniform disease and that understanding the characteristics of different subtypes could help provide more effective treatments for patients.Focus on biological clock
The research underscores the importance of the body's internal clock, which regulates the alternation between wakefulness and sleep, and suggests that targeting the wake-sleep rhythm could be a more effective management approach for this specific subtype of depression.
