0328 The Natural History of Insomnia: High Sleep Reactivity Interacts with Greater Life Stress to Predict the Onset of Acute Insomnia

Abstract

Abstract Introduction Previous studies have shown that stressful life events are the primary trigger in the development of insomnia. One etiological model of insomnia suggests that sleep reactivity, or the vulnerability to stress-related sleep disturbance, may be an important moderator of this association. That is, some individuals have a predisposition to experience insomnia following acute stressors (i.e., sleep reactivity). The goal of the present study was to provide a proof of concept and, specifically, additional empirical evidence that the link between stressful life events and the onset of acute insomnia is moderated by sleep reactivity. Methods 1,225 adults with a history of good sleep (Mage = 53.2 years, 68% female, 83% white) were recruited nationwide for an online study on sleep health. Participants completed surveys to assess sleep reactivity (baseline), sleep patterns (daily sleep diaries), and stressful life events (weekly survey). This high-density data (daily/weekly measures) allowed for a close examination of whether sleep reactivity predicts acute insomnia and how the association between stressful life events and sleep disturbance varies as a function of sleep reactivity. Due to the high variability of stressful life events and sleep over time, frequent data points were needed to test this etiological model of insomnia. Sleep diary data were used to identify sleep initiation/maintenance difficulties, including whether they met criteria for acute insomnia at any point during the one-year interval. Results Participants with high sleep reactivity, compared to low sleep reactivity, were at 76% increased odds of developing acute insomnia during the one-year interval. In general, greater weekly stressful life events were associated with greater insomnia during the subsequent week. Additionally, those participants with high sleep reactivity demonstrated a stronger relationship between weekly stressful life events and insomnia, such that they reported the greatest levels of insomnia following weeks where they experienced a greater number of stressful life events. Conclusion These results further support the sleep reactivity model of insomnia, and specifically, provide evidence that sleep reactivity predicts the incidence of acute insomnia in a sample of participants with no history of insomnia. Support (if any) Perlis: R01AG041783, K24AG055602; Vargas: K23HL141581, R25HL10544