Researchers from Australia have refined the understanding of the circadian subtype of depression, in which disruptions to circadian rhythms are the primary cause of mood disorders. As part of their work, they proposed a number of diagnostic criteria for this condition.
The proposed criteria include signs such as social jetlag, seasonal fluctuations, a shift in average sleep time to a later period, the presence of an evening chronotype, as well as morning fatigue and excessive daytime sleepiness.
Furthermore, the scientists established a link between this type of depression and an increased polygenic risk for various mental illnesses. The study results were published in the scientific journal The British Journal of Psychiatry.