Researchers identify circadian depression subtype in patients
The study found that about one in four people with depression fit a new circadian subtype linked to disrupted body clocks, suggesting light therapy and melatonin could be more effective than standard antidepressants.
21 Oct 2026 0 reads Compiled with AI
#circadian depression #University of Sydney #Australian Genetics of Depression Study
A study from the University of Sydney, published in the British Journal of Psychiatry, identified a new circadian subtype of depression. The researchers found that about one in four people with depression fall into this category, based on data from 11,380 participants in the Australian Genetics of Depression Study.
Patients with the circadian subtype show symptoms that shift with the seasons, have a delayed sleep midpoint, and experience social jet lag—meaning their sleep timing on workdays differs from non‑workdays. They tend to be evening chronotypes and report feeling very tired in the morning.
These individuals often experience depression earlier in life and report more severe clinical features, such as mania, psychosis, and suicidality. They also have higher genetic risk for neurodevelopmental disorders and are less likely to respond to conventional antidepressants. Because the condition is linked to circadian rhythms, clinicians may consider light therapy or melatonin as alternative treatments.