0137 Cognitive and Somatic Pre-Sleep Arousal are Associated with Fear of Sleep in Acute Trauma Patients

Abstract Introduction Trauma-exposed individuals with PTSD may develop a fear of sleep (FoS). FoS is defined as a fear of being vulnerable during sleep and is accompanied by elevated pre-sleep arousal. Pre-sleep arousal is classified into two subscales – cognitive, the psychological response such as depressing or anxious thoughts, and somatic, the physiological response such as increased heart rate and shortness of breath. However, it is unclear if FoS is driven by overall pre-sleep arousal or predominantly cognitive or somatic arousal specifically. We investigated whether cognitive and somatic pre-sleep arousal independently predict fear of sleep among patients hospitalized following traumatic injury. Methods We recruited patients hospitalized in a Level I trauma center in Detroit, Michigan, following traumatic injury (N = 88, Mage = 39.53 ± 14.31, 67.0% male, 67.0% Black). Patients completed the Pre-sleep Arousal Scale (PSAS) and the Fear of Sleep Inventory (FoSI) Short Form during hospitalization. The FoSI queried patients about their fear of sleep over the past 30 days (e.g., “I felt that it was dangerous to fall asleep”). We conducted a hierarchical regression to assess the independent relationship between each PSAS subscale and FoS. Results Our sample had a FoS mean score of 8.56 (SD=9.48) of a maximum score of 52. Our sample had a cognitive mean score of 15.49 (SD=7.46) of a maximum score of 40, and a somatic mean score 21.17 (SD=9.10). Our sample had higher cognitive than somatic arousal (t=7.87,p<.001). Cognitive and somatic subscales were highly correlated (r=.68, p<.001). In a linear regression, both cognitive (β=0.45, 95% CI [0.21,0.69], p<.001) and somatic (β=0.23, 95% CI [-0.05,0.52], p<.05) subscales independently predicted FoS and the model explained 41% of the variance. Conclusion Both cognitive and somatic arousal before sleep are uniquely associated with fear of sleep among acute trauma patients hospitalized in a Level I trauma center. These findings suggest that treatment may not need to target a specific type of arousal at bedtime. Instead, interventions aimed at reducing pre-sleep cognitive arousal, such as mindfulness, or pre-sleep somatic arousal, such as relaxation, may both help ameliorate fear of sleep in acute trauma patients. Support (if any) K23MH134032 (A.N.R.).