After years of thinking that insomnia was a side effect of depression, experts have finally found a clearer link between bleary-eyed nights and extreme sadness.
"Insomnia is more than a symptom; it's a risk factor for major depression," says Dr. Michael Perlis, director of the University of Rochester Sleep and Neurophysiology Research Lab, and author of two studies linking insomnia and depression. The important suggestion, he adds, is that fixing sleep problems may help prevent an emotional slide and often a much easier task than treating depression itself.
Insomnia and Depression
One study, presented at a 2005 meeting of the Associated Professional Sleep Societies, looked at data from over 1,800 men and women aged 65 or older and found that depressed patients with insomnia were 17 times more likely to remain depressed a year later as compared to those who were sleeping well.
Elderly patients are often the focus of depression research as it is estimated that over 2 million older adults are affected, and 18 percent of all suicide deaths occur in this population. Previous studies have also shown that 42 percent of older adults have some sort of trouble sleeping.
This first finding confirmed the belief that there is a link between insomnia and depression, but much like the chicken versus egg debate, it still did not explain which came first—the depression that causes insomnia or the insomnia that leads to depression.
So, in a different study, Perlis surveyed 147 elderly patients and found that those with insomnia and no history of depression are six times more likely to experience depression than people who sleep through the night. Interestingly, women with a particular type of insomnia had the strongest association with future depression.
Understanding the Power of Insomnia
There are three types of insomnia. The people found to be most at risk for depression suffered from "middle insomnia." a condition where one can fall asleep but still wakes frequently during the night. While the reason this type of insomnia is a stronger predictor remains unclear, scientists have some theories as to how insomnia develops into depression.
Health
For one, the loss of control over sleep becomes unsettling to patients, says Perlis, and in an effort to regain control, people tend to try to nap or oversleep to compensate for the lost hours. This throws your entire system off, making it even harder for you to fall asleep the next night. Even when the stresses that are causing the insomnia go away, the inability to sleep lingers.
The remedy, Perlis says, is understanding that insomnia is a serious problem when it lingers. If the sleepless nights last for more than a week, be sure to see a doctor for rapid and aggressive treatment to prevent a lack of sleep from turning into something much more serious.
"[Insomnia] is something that should be targeted for treatment directly," says Perlis.
