New research reveals that sleep problems that are often a symptom of depression, could also increase the possibility of depression.
Men with undiagnosed, severe obstructive sleep apnoea (OSA) ran double the risk of depression as against those without sleep apnoea, according to study researcher Carol Lang, a research fellow in the department of medicine at the University of Adelaide in Australia.
According to the researchers, certain aspects of post traumatic stress disorder (PTSD), such as disturbed sleep and sleep deprivation, psychological and physical stressors of combat and hyper arousal due to those stressors, might up the chances of occurrence of sleep apnoea.
According to study author Dr Carol Lang, excessive daytime sleepiness and severe OSA were both associated with the prevalence and recent onset of depression in their community-based sample of men, and the presence of both was associated with an even greater risk.
Further, it was the men whose sleep issues had gone disregarded that had the highest chances of eventually developing depression.
The study authors wrote, "Men with previously undiagnosed OSA and EDS had 4.2 times greater odds of depression than subjects without OSA and EDS and 3.5 times greater odds of depression than individuals with either OSA or EDS alone."
The study involved 2,000 Australian men between the ages of 35 and 83.
Those with excessive daytime sleepiness were 10 per cent more likely to be depressed than those without, according to researchers from the University of Adelaide and the Adelaide Institute for Sleep Health. The relationship held true even after taking other risk factors into account.
According to the study, clinical depression might accelerate the aging process.
At the start of the study none of the men had been diagnosed with severe obstructive sleep apnoea, but 857 of them were assessed for the condition after their joining.
Those who were found to have it were 2.1 times more likely to be depressed than those who did not suffer from sleep disorder.
The men in the study were evaluated for depression twice, with the second test occurring about five years after the first, which allowed the researchers to see whether sleep problems could be linked to a recent diagnosis of depression.
The researchers discovered that men who had severe sleep apnoea that was discovered during the study were 2.9 times more likely to become depressed during those five years.