Scientists are learning why insomnia and depression are so closely interconnected. Sleep disturbances, especially early morning awakenings, are a common symptom of depression. An Ohio State University study suggests that these symptoms are related to an over-active body clock.
The so-called Clock gene helps regulate the body’s circadian rhythms. Molecular-level disturbances in the Clock gene may disrupt the 24-hour body clock, causing sleep problems.
The study compared the blood samples of people with a history of depression to those who had never been clinically depressed. The study included 60 participants; 25 spent at least five hours per week caring for a family member with dementia.
Blood analysis shows people with a history of depression had higher levels of the Clock gene. The relationship held true after statistical adjustments for age and lifestyle factors such as substance use, exercise, medical conditions and caregiving status.
Researchers also analyzed three other circadian genes, but found no statistically significant differences in gene levels between depressed and non-depressed subjects.
The authors of the study caution that the findings demonstrate there is a link, but causal direction remains unclear. In other words, further research is needed to determine whether depression causes the clock gene to be elevated, or vice versa.
Researchers explain their findings are simply a snapshot of how gene activity differs between people with and without depression.
Several other studies have attempted to explain the link between insomnia and depression.
A study published in the September 2010 issue of SLEEP suggests sleep deprivation causes depression in young adults. Every hour of sleep lost significantly raises the risk of emotional distress, a combination of high levels of depressive and anxious symptoms.
Another study presented at SLEEP 2010 in San Antonio reported similar findings, but for teenagers. Students who reported problems with daytime sleepiness were three times more likely to have depression compared to their peers.
In any case, the treatment options for depression and insomnia often overlap. While medication can help in the short term, cognitive-behavioral therapy is the best approach for lasting results. Conquering depression and insomnia takes a lot of work, but your health and happiness are worth the effort.