April 4, 2008

Science Daily/American Academy of Sleep Medicine

In addition to being a risk factor for a depressive episode, persistent insomnia may perpetuate the illness in some elderly patients, and especially in those receiving standard care for depression in primary care settings, according to a new study.

According to the results, patients with persistent insomnia were 1.8 to 3.5 times more likely to remain depressed, compared with patients with no insomnia. The findings were more robust in patients receiving usual care for depression than in patients receiving enhanced care. The findings were also stronger in subjects who had major depressive disorder as opposed to those with dysthymia alone.

"Even when depression was identified and treated in the primary care setting, the older adults in this study were more likely to remain depressed if they also exhibited persistent insomnia.

The finding that this risk was higher in the usual-care group suggests that enhanced depression care may partially mitigate the perpetuating effects of insomnia on depression," said Dr. Pigeon.

"While the findings make intuitive sense, until relatively recently insomnia was often considered a symptom that dissipated without active intervention once a primary condition like depression was treated, instead of being considered a distinct clinical entity that might affect a primary disorder. This study has several limitations, not the least of which are that it is not a causal study nor does it unequivocally answer the question of whether insomnia that presents with depression is a symptom or a co-morbid disorder. What seems most likely is that insomnia is indeed simply a symptom in some cases, but clearly a disorder requiring its own treatment focus in other cases."

Not sleeping well can lead to a number of problems. Older adults who have poor nighttime sleep are more likely to have a depressed mood, attention and memory problems, excessive daytime sleepiness, more nighttime falls and use more over-the-counter or prescription sleep aids. In addition, recent studies associate lack of sleep with serious health problems such as an increased risk of obesity, cardiovascular disease and diabetes.

http://www.sciencedaily.com/releases/2008/04/080401081930.htm