One of the first questions doctors ask patients who appear depressed is, ‘How’s your sleep?’ That’s because insomnia and/or excessive slumber are tell tale signs of major depressive disorder.
A new study, “Circadian patterns of gene expression in the human brain and disruption in major depressive disorder,” explains why this is so. The study found that the brains of people suffering from major depression are out of sync with normal circadian rhythms. How did they figure this out? Researchers analyzed donated brain tissue from depressed and non-depressed people and found that in the normal brains, the internal clocks ran on time. In the brains of severely depressed patients, however, the circadian clock was so disrupted that day often became night and vice versa.
Why? “We can only glimpse the possibility that the disruption seen in depression may have more than one cause. We need to learn more about whether something in the nature of the clock itself is affected, because if you could fix the clock you might be able to help people get better,” Huda Akil, one of the authors of the study, told Science Daily.
Doctors often prescribe medication or light therapy to help depressed patients get their clocks back to a normal cycle. This is wise medicine. Feeling sad and exhausted is double trouble.