Insomnia and depression often go hand-in-hand. Although just 15% of people with depression sleep too much, as many as 80% have trouble falling asleep or staying asleep. Patients with persistent insomnia are more than three times more likely to develop depression.
The relationship between insomnia and depression is far from simple, however. “Until recently, insomnia was typically seen as a symptom of depression,” says Michael L. Perlis, MD, an associate professor of psychiatry and director of the Behavioral Sleep Medicine Program at the University of Pennsylvania. “Treat the underlying depression, the thinking went, and sleep problems would go away.”
But new research shows that insomnia is not just a symptom of depression. “What we’ve come to understand is that insomnia and depression are two distinct but overlapping disorders,” says Perlis. Research shows that by treating both simultaneously, doctors have a better shot at improving a patient’s sleep quality, mood, and overall quality of life.
Can Insomnia Trigger Depression?
It’s easy to understand how insomnia might be linked to depression. “Chronic sleep loss can lead to a loss of pleasure in life, one of the hallmarks of depression,” explains Stanford University research psychologist Tracy Kuo, PhD. “When people can’t sleep, they often become anxious about not sleeping. Anxiety increases the potential for becoming depressed.”
Indeed, recent findings show that insomnia often shows up before a bout of depression strikes, serving as a useful warning sign. A worsening of insomnia can also signal depression.
But the relationship is far more than simply cause and effect. When depressed people suffer from insomnia, their risk of recurring depression is greater than that of patients who don’t have insomnia. “So insomnia may serve as a trigger for depression,” Perlis says. “But it also appears to perpetuate depression.”