- A diagnosis of sleep apnea was associated with depression in both men and women in a study using National Health and Nutrition Examination Survey data.
- Note that self-report of snorting and stopping breathing, but not snoring, also were associated with risk of depression, but the cross-sectional design precluded assigning causality.
Both men and women with obstructive sleep apnea are at elevated risk for major depression, a large nationwide survey revealed.
Men who reported having been diagnosed with sleep apnea had twice the risk of depression (OR 2.4, 95% CI 1.5 to 3.6, P<0.05) compared with those without apnea, according to Anne G. Wheaton, PhD, and colleagues from the Centers for Disease Control and Prevention.
And for women, the risk for depression was fivefold higher with sleep apnea (OR 5.2, 95% CI 2.7 to 9.9, P<0.05), the researchers reported in the April issue of Sleep.
Obstructive sleep apnea has been linked with depression in some small studies and in limited populations such as Veterans Health Administration patients, and some research has found that depression improved in patients with sleep apnea who were treated with continuous positive airway pressure.
However, whether there is an association in the general population has been unclear.
So Wheaton’s group analyzed data from the National Health and Nutrition Examination Surveys from 2005 to 2008, identifying 9,714 individuals who provided information about demographics, sleep, and depression.
Almost three-quarters were white, one-quarter had college degrees, and 16% were 65 or older.
A total of 72% of men were overweight or obese, as were 63% of women.
Among men, 6% had been given a diagnosis of sleep apnea, as had 3.1% of women.
More men than women reported snoring more than five nights per week (37.2% versus 22.4%).
Men also more commonly reported snorting or stopping breathing while sleeping at least once a week (22.7% versus 15.4%) or five or more times a week (7.1% versus 4.3%).
Notably, more than 80% of individuals who frequently snorted or stopped breathing had never been given a diagnosis of obstructive sleep apnea, according to the researchers.
Depression, as assessed on a 9-item patient health questionnaire, was identified in 8.4% of women and 5% of men.
Simple snoring did not increase the risk of depression, but snorting or stopping breathing five or more nights each week tripled the risk for both men (OR 3.1, 95% CI 1.8 to 5.2) and women (OR 3, 95% CI 1.6 to 5.4, P for trend <0.001).
Both men and women were more likely to have responded positively to all 9 items on the depression questionnaire if they reported snorting or stopping breathing at least once weekly (P<0.05).
The item on the depression questionnaire that was most closely linked with snorting or stopping breathing was how often in the previous 2 weeks they had felt down, depressed, or hopeless, with an odds ratio of 1.9 for men (95% CI 1.4 to 2.6) and 2.5 (95% CI 1.8 to 3.4) for women.
A possible explanation for why patients with sleep apnea are at risk for depression lies in the hypoxia that they may experience, according to the authors.
“Episodic hypoxia from [obstructive sleep apnea] has been linked to altered neuronal activity and decreased gray and white matter in the brain, possibly through induction of oxidative stress, inflammation, or endoplasmic reticulum stress,” they explained.
A limitation of the study was its cross-sectional design, so the researchers were unable to determine causality. In addition, sleep symptoms were self-reported, and there was a lack of information about treatment for either depression or sleep apnea.
The researchers called for further studies to determine whether sleep specialists ought to screen patients for depression, and whether the efficacy of treatment for sleep apnea could be increased if accompanied by treatment of depression.
“Sleep is essential and healthy sleep should be as important as healthy nutrition, physical activity, and smoking cessation in promoting overall health,” Wheaton and colleagues concluded.
The lead author was supported by the Association for Prevention Teaching and Research and the Centers for Disease Control and Prevention.
The authors had no financial conflicts of interest.
Primary source: Sleep
Wheaton A, et al “Sleep disordered breathing and depression among U.S. adults: National Health and Nutrition Examination Survey, 2005-2008″ Sleep 2012; 35: 1-7.
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