Study Identifies "Circadian Depression" Subtype in One in Four Depression Cases
A study that came out on October 21 in the British Journal of Psychiatry reveals that around 25% of people battling depression might be dealing with something called "circadian depression," linked to an irregular body clock. Emiliana Tonini led this investigation, surveying over 11,000 Australians who were severely depressed. Out of these, 2,604 met at least three out of five criteria, including morning sleepiness and social jet lag. This group showed higher genetic risks for ADHD and mood disorders, experienced stronger symptoms earlier in life, and had a weaker response to medications like Prozac. Co-author Ian Hickie suggested focusing on treatments that target the circadian system, though some critics raised concerns about the self-reported data and sample diversity.
Key facts
- Study published in the British Journal of Psychiatry on October 21
- More than 11,000 Australians of European descent with severe depression were surveyed
- 2,604 participants met at least three criteria for circadian depression
- Criteria include morning sleepiness, delayed sleep timing, social jet lag, excessive sleeping during depressive episodes, and seasonality
- Subtype group showed higher genetic risk for ADHD and mood disorders plus metabolic and inflammatory markers
- Those with the subtype were less likely to respond to SSRIs such as Prozac
- Sample was limited to people of European ancestry and relied on self-reported symptoms
- Co-author Ian Hickie is a psychiatrist at the University of Sydney
Entities
Artists
- Emiliana Tonini
- Ian Hickie
- Colleen Loo
- Andrew Coogan
- Lauren Roberts
- Alice Klein
- Donna Lu
- Euan Black
- Rachel Fieldhouse
- Sara Hashemi
Institutions
- British Journal of Psychiatry
- Australian Broadcasting Corporation
- New Scientist
- Guardian
- Financial Review
- University of Sydney
- University of New South Wales
- Maynooth University
- Nature
- Smithsonian Magazine
Locations
- Australia
- Sydney
- Ireland
- New York City
- United States