INSIGHT: Insomnia, Nightmares, and Sympathetic Hyperactivity Intervention

The INSIGHT study is a multi-site clinical research program designed to examine how insomnia and symptoms of sympathetic hyperactivity impair sleep, cognition, and physiological restoration in warfighters, and to evaluate whether a wearable therapeutic device can improve these outcomes. Warfighters with a history of traumatic brain injury, post-traumatic stress disorder, or chronic operational stress commonly report disrupted sleep accompanied by manifestations of nocturnal sympathetic activation such as diaphoresis, palpitations, hyperarousal, and nightmares. These symptoms erode sleep quality, reduce cognitive performance, and undermine psychological resilience and operational readiness. Insomnia is two to three times more common in military populations than in civilians, and both TBI and PTSD independently elevate the risk for dysregulated autonomic tone. Excessive sympathetic activity during REM sleep disrupts the normally quiescent locus coeruleus state required for adaptive emotional processing and may contribute to the genesis of nightmares. Excessive sympathetic tone may also interfere with deep NREM-dependent glymphatic clearance, a recently discovered mechanism that supports cognitive restoration and metabolic waste removal. Yet, no study has comprehensively linked these physiological processes in warfighters or evaluated whether wearable-derived autonomic measures can meaningfully stratify insomnia phenotypes. The INSIGHT protocol addresses this gap through a two-phase design integrating multimodal biomarker collection, wearable technology validation, advanced imaging, and a randomized controlled intervention. Phase 1 enrolls 250 participants (50 healthy controls and 200 poor sleepers with or without PTSD and TBI) who undergo structured screening, cognitive testing, and detailed baseline assessments before completing a 2-week at-home data collection period. During this period, participants wear a suite of devices, including EEG headbands, ECG patches, PPG