How Stress Causes Insomnia

Recent reports support the theory that insomnia often is associatedwith a hyperarousal state marked by increased activation ofthe hypothalamic-pituitary-adrenal (HPA) axis. In a study presentedat the Associated Professional Sleep Societies 19th Annual Meeting(June 2005), patients with insomnia demonstrated a 71% greateradrenocorticotropic hormone response, which results in higherlevels of secreted cortisol, compared with the patients in the controlgroup. The investigators concluded that the data reflected theHPA dysregulation or hyperarousal state seen in primary insomnia.

Cortisol increases when individuals have physical or psychologicalstress, which tends to drive sleeplessness. Cortisol raises bloodsugar and ensures that enough energy is produced to deal withstress factors. Treatments that address the hyperarousal state ofinsomnia may not only improve the quality or quantity of sleep butalso reduce the risk of developing psychiatric or medical illnessesassociated with hyperarousal.