Australian researchers identify new subtype of depression linked to body clock disruptions Study identifies ‘circadian depression’ as affecting nearly a quarter of more than 11,000 participants

https://www.theguardian.com/society/2026/oct/21/australian-researchers-identify-new-subtype-of-depression-linked-to-body-clock-disruptions?utm_source=Live+Audience&utm_campaign=989765235e-nature-briefing-daily-20261021&utm_medium=email&utm_term=0_-33f35e09ea-50432164 Body clock linked to 1 in 4 depression cases A study of more than 11,000 people with depression found that a quarter had a new subtype that makes their condition hard to treat. ‘Circadian depression’ appears to be linked to disruptions in the body’s internal clock, which could be targeted with treatments such as melatonin and light therapy. “Circadian depression is not just depression with bad sleep,” said neuroscientist and study co-author Emiliana Tonini. “There is an underlying biology that is quite distinct from other forms of depression.”