Insomnia and the Stress System
In the last two decades, several models have been proposed to understand the etiology and pathophysiology of insomnia and most of them have emphasized the importance of the joint effect of stress and psychological factors in the pathogenesis of insomnia.14 The characteristic psychological profile of patients with insomnia, consisting of cognitive-emotional hyperarousal (i.e., obsessive, anxious, ruminative, and dysthymic personality traits) and emotion-oriented coping strategies,14-16 is thought to be present pre-morbidly and play a key role in the etiology of the disorder.14,17-20 Insomnia is associated with precipitating life events21 and cognitive-emotional arousal14 and is perceived by the patient as stressful on its own. Thus, insomnia should be expected to be associated with activation of the stress system.