Research shows that when we don't sleep well we're at greater risk for accidents, weight gain, depression, diabetes, hypertension, heart disease, stroke, and overall premature mortality. While well more than half of all Americans have trouble sleeping, the effects of sleep loss hit women a lot harder than men. For instance, recent research suggests that when women lose sleep, they gain more weight than men. And there's more: Last year a British study found that sleep loss puts women at greater risk for hypertension than it does men. In a German study, sleeping five hours or less a night tripled women's risk for heart attacks, but not men's. And earlier this year researchers at Duke University in Durham, North Carolina, showed that women who took longer than 30 minutes to fall asleep had blood levels of C-reactive protein elevated enough to be associated with a high risk for heart disease. "It appears that sleep loss may be indicative of a disruption of the process by which the amino acid tryptophan is converted into serotonin and then into melatonin, a hormone that promotes sleep," says Edward C. Suarez, Ph.D., associate professor of psychiatry and behavioral sciences at Duke University Medical Center, who led the study. Women, it turns out, are far more sensitive than men to these disruptions, which then ripple out to influence appetite and weight, blood platelet stickiness and inflammation in the body (both which may affect the risk of heart attack and stroke), and mood. When men in the Duke research program didn't sleep well, they showed no signs of stress. The women? They got angry and depressed.
Fuming on the couch as my husband snored away in the bedroom, I would certainly attest to the rage. And I worried about depression, too, because it runs in my family: My sister, mother, and grandmother have all experienced the condition. Doctors used to believe that insomnia stemmed from depression, but now it's thought that it can work the other way, or that the two can go hand in hand. According to a recent University of Pittsburgh study that followed about 600 people for 20 years, up to 50% of those who had insomnia for more than two weeks experienced major depression later on. I had already gone through one terrible bout of depression about five years earlier, and I didn't want my insomnia to trigger another one.