Abstract Introduction Insomnia following Traumatic Brain Injury (TBI; TBI insomnia) is a common problem, with prospective studies finding that more than half of individuals developed insomnia within the first three months of injury. Individuals with TBI are also at higher risk for psychiatric symptom development and demonstrate greater nicotine use (OR= 2.15) compared to individuals without a history of TBI. Nicotine use is further associated with disrupted sleep, negatively impacting sleep through its effects on arousal-promoting neurotransmitters (e.g., dopamine, norepinephrine, acetylcholine, etc.), sympathetic nervous system activation, potential circadian dysregulation, and sleep architecture disruption. And yet, despite greater rates of psychiatric symptoms and nicotine use following TBI and the deleterious impacts of nicotine use on sleep, to our knowledge no work has explored the associations of nicotine status and psychiatric symptoms with sleep in individuals with TBI insomnia. Methods We analyzed baseline data from a community sample of TBI patients with insomnia (N=48, Mage=39.8 ±12.9, 65% female) enrolled in a parent RCT comparing 4-session CBT-I to sleep education. Participants self-reported nicotine use, with 15% and 17% (N=7 and 8) endorsing current and former nicotine use. Hierarchical multiple regression examined the associations between 1) psychiatric symptoms and subjective sleep quality and 2) psychiatric symptoms, nicotine use status, and subjective sleep quality. Results On average, participants endorsed mild anxiety symptoms (MGAD-7: 6.4 ±5.2), moderate depressive symptoms (MPHQ-9: 10.1 ±5.2), and poor sleep quality (MPSQI: 12.4 ±3.2). In the initial model, psychiatric symptoms were significantly associated with worse subjective sleep quality (F(2, 45)=6.33, p=0.004, R2=0.22). Adding nicotine use status in the second model significantly improved model fit (p=0.03, ∆R2=0.11). After adjusting for psychiatric symptoms, subjective sleep quality differed significantly by nicotine use status, with current nicotine users reporting significantly worse sleep quality than never users (p=0.041). Conclusion Individuals with TBI insomnia who currently use nicotine are at greater risk for worse sleep quality and greater sleep disturbances, even after accounting for co-occurring anxiety and depressive symptoms. These findings highlight the importance of targeted screening and policy efforts to reduce nicotine exposure, address psychiatric symptoms, and improve insomnia outcomes following TBI. Support (if any) AASM Foundation SRA I.
Steffens et al. (Fri,) studied this question.