Health · Medical Research · 4 hrs ago
Study identifies a possible circadian-linked form of severe depression
Australian researchers found signs of a circadian-linked form of depression in a study of more than 10,000 people with severe depression.
About 23% met at least three of six signs of a disrupted body clock, including late bedtimes, morning tiredness and changes in sleep or mood across seasons.
The body clock helps regulate sleep and daily activity, and disruptions may be linked to symptoms such as low energy and poor sleep.
The group had more severe symptoms on average, and standard antidepressants appeared less effective and caused more side effects.
The findings are preliminary, and researchers say more work is needed before this is formally recognized as a depression subtype.
Researchers plan to test melatonin as a possible treatment, while morning sunlight and other approaches targeting sleep timing may also be studied.
An Australian study found that 23% of more than 10,000 people with severe depression met criteria for a possible circadian-linked subtype.
The subtype was identified by at least three of six signs involving sleep patterns, morning fatigue and seasonal changes in mood, energy, sleep or appetite.
People in this group had more severe symptoms, earlier onset and a weaker reported response to standard antidepressants, with more side effects.
Researchers say the findings could support more tailored treatments, including approaches that target the body clock.
Further research is needed before circadian depression can be formally recognised as a subtype.
- Who
- Australian researchers studied people with severe depression; 23% met criteria for the proposed subtype.
- What
- The study identified a possible form of depression linked to circadian rhythm disruption.
- When
- The study was reported in October 2026; the sources do not state when the research was conducted.
- Where
- The research was conducted in Australia.
- Why
- Researchers sought to identify whether circadian disruption marks a distinct depression subtype and could inform treatment.
This story does not have two clearly opposing sides.
Courrier international reported the Australian study's findings, including that 23% of participants met the proposed subtype criteria.
Slate.fr reported that researchers were preparing a clinical trial to test whether melatonin could help treat circadian-linked depression.
Le Soleil reported on the possible clinical implications, including the group's weaker reported response to standard antidepressants.
- Study participants
- More than 10,000 people with severe depression
- Proposed subtype share
- 23%
- Criteria
- At least 3 of 6 circadian disruption signs
- Publication
- British Journal of Psychiatry
- Potential treatment
- Melatonin and other approaches targeting the circadian system
3 sources
What people are saying
We live in an era that encourages us to stay indoors, spend our days in front of a computer, avoid light, then stay up at night and expose ourselves to it. That's the opposite of what we're made for.
And what is particularly interesting is that this leads us to think about how we treat these types of depression.
These results are really useful because they advance the field in understanding the circadian rhythm aspect of depression and how it could be linked to biological measures such as genetics and inflammatory markers.