Insomnia may precede and prolong major depression

Two new studies show that insomnia, far from being a symptom or side effect of depression, may instead precede it, making some patients more likely to become and remain mentally ill. One paper was presented today at the 19th Annual Meeting of the Associated Professional Sleep Societies (APSS) in Denver, and the other will be published shortly in the Journal of Behavioral Sleep Medicine.

In recent years, researchers established that insomnia and depression are linked, but struggled to determine which came first. Many experts believed that depression caused insomnia until new drugs arrived that improved depression, but not insomnia. The idea that insomnia could be a contributor to, or predictor of, depression gained credence.