Can long-term mental stress cause insomnia?
Yes, chronic psychological stress is a well-established risk factor for the development and exacerbation of insomnia disorder. Prolonged activation of the hypothalamic-pituitary-adrenal (HPA) axis leads to elevated cortisol levels, particularly in the evening or at night, which disrupts normal sleep-wake regulation. This neuroendocrine dysregulation impairs sleep onset, reduces slow-wave (N3) and rapid eye movement (REM) sleep continuity, and increases nocturnal awakenings. Additionally, persistent cognitive hyperarousal—characterized by rumination, worry, and heightened vigilance—interferes with the physiological transition from wakefulness to sleep. Over time, these maladaptive patterns can become conditioned, resulting in learned sleeplessness even after the initial stressor has resolved. Clinical guidelines, including those from the American Academy of Sleep Medicine (AASM) and the European Sleep Research Society (ESRS), recognize stress-related insomnia as a distinct phenotype within chronic insomnia disorder, warranting integrated management that addresses both behavioral and physiological contributors.