Trauma, Hyperarousal, and Sleep: Neurobehavioral Pathways in Affective Disorders

Sleep disturbances are common across affective disorders and may coexist with traumatic stress and persistent hyperarousal. This narrative review examines how trauma-related hyperarousal and sleep dysfunction are associated with major depressive disorder (MDD) and bipolar disorder (BD), while distinguishing observed associations from proposed mechanisms. A targeted search of PubMed, Scopus, and Google Scholar identified clinical, neurobiological, and translational literature on trauma, hyperarousal, insomnia, nightmares, circadian disruption, MDD, and BD. The evidence supports a multidimensional view of hyperarousal involving partly overlapping autonomic, cognitive-attentional, affective, and behavioral domains; however, it does not establish hyperarousal as a unitary mechanism or justify equating trauma-related vigilance with manic activation. Sleep disturbance may function as a symptom, vulnerability factor, or prodromal change, but no single sleep measure is currently a validated individual-level prognostic marker. Clinically, trauma history, sleep phenotype, affective state, comorbidity, medication effects, and current safety should be assessed jointly. Cognitive behavioral therapy for insomnia and established trauma-focused treatments have the strongest clinical basis within their indicated populations, whereas imagery rehearsal therapy, prazosin, chronobiological strategies, and candidate biomarkers require diagnosis-specific and evidence-graded interpretation. Longitudinal studies integrating objective sleep measures and explicit temporal modeling are needed before proposed pathways or precision approaches can be considered clinically validated.