Scientists have discovered a new type of depression. It has to do with the biological clock

In a study published in the British Journal of Psychiatry, Australian scientists analyzed the clinical and genetic data of over 11,000 people with severe and recurrent depression. The results are surprising - as many as 23 percent. participants showed symptoms of a newly identified subtype called "circadian depression".

What is circadian depression?

This type of depression is characterized by disturbances in the circadian rhythm, i.e. the natural cycle of sleep and wakefulness.

People affected by this subtype exhibit at least three of six specific characteristics:

seasonal nature of the disease,

delayed falling asleep,

prolonged sleep during depressive episodes,

tendency to be nocturnal,

feeling extremely tired after waking up,

"social jetlag", i.e. a significant difference in sleep hours on working days and holidays.

Symptoms and consequences

Researchers emphasize that people with circadian depression experience not only an earlier onset of the disease, but also a greater number of episodes and a more complex course. These patients are more likely to experience suicidal thoughts, hypomanic symptoms, and psychotic symptoms. Importantly, they also have a higher genetic risk for ADHD and other mood disorders, as well as elevated metabolic and inflammatory markers.

This finding suggests that circadian depression is not just depression with sleep problems, but is a distinct, biologically determined subtype of the disease.

Treatment effectiveness

One of the most disturbing findings from the study is the low effectiveness of traditional antidepressants, such as SSRIs and SNRIs, in treating circadian depression. Patients with this subtype are not only less likely to respond to standard therapies, but also more likely to experience side effects.

Experts indicate that in the case of circadian depression, therapies aimed at regulating the circadian rhythm may be crucial. Recommended methods include light therapy, melatonin supplementation, recurrification of the sleep-wake cycle, and a set schedule of meals and physical activity.

The discovery of a new subtype of depression opens the way to a more personalized approach to the treatment of mood disorders. Scientists emphasize that the ability to clinically diagnose circadian depression may be particularly helpful in young people who are seeking psychiatric help for the first time.