Default-mode network activity and its role in comprehension and management of psychophysiological insomnia: A new perspective

Psychophysiological insomnia (PI) is a common sleep disorder in which numerous variables interact. The mechanisms responsible for the etiology and maintenance of PI, though far from completely understood, point to the existence of hyperarousal of several systems. The frequent occurrence of ruminations and worries with a self-referential component (related or not with sleep complaints) during the pre-sleep period, and daytime wakefulness, seems to relate to the functions which have been associated with default-mode network (DMN) activity. This neural network seems to be involved in introspective thinking as well as emotional and episodic memory processing, among others. In this paper, we propose that PI may be conceptualized as a disorder associated with overactivity of some brain areas of DMN. Accordingly, it is also suggested that cognitive-behavioral therapy for insomnia (CBT-I), a kind of non-pharmacological treatment, may alter the function of this network, improving symptoms of patients, and overall quality of life.