Reduced Sleep Quality Can Aggravate Pre-existing Psychological Conditions

To effectively evaluate differences in sleep architecture after induced stress, Robert Ross MacLean, of Boston University, utilized an objective measure of anxiety and recorded subsequent sleep-wake behavior in rats. In the rodent model, many previous studies had observed differences in sleep-wake behavior after shock exposure, but the level of anxiety was merely assumed or absent.

MacLean's study exposed naïve rats to one of three paradigms: escapable shock, inescapable shock or fear conditioning. Immediately after experimental manipulation, individual level of anxiety was assessed using the elevated-plus maze apparatus, and polygraphic signs of sleep-wake behavior were recorded for six hours.

By measuring individual anxiety level prior to recording sleep, MacLean was able to make comparisons between sleep architecture and level of anxiety. In doing so, MacLean intended to establish a direct link between variation in sleep architecture and heightened anxiety in the rodent model.

"These changes could elucidate sleep-wake behavior associated with the subjective complaint of disrupted sleep, thus creating the potential for new diagnostic and assessment criteria for anxiety disorders," said MacLean. "This information is relevant given the recent influx of psychological disorders in Iraq war veterans, particularly generalized anxiety and post-traumatic stress disorder."

The amount of sleep a person gets affects his or her physical health, emotional well-being, mental abilities, productivity and performance. Recent studies associate lack of sleep with serious health problems such as an increased risk of depression, obesity, cardiovascular disease and diabetes.

An abstract of this research was presented June 13 at SLEEP 2007, the 21st Annual Meeting of the Associated Professional Sleep Societies (APSS).