Casement, MelyndaKelly, Shay2024-08-072024-08-072024-08-07https://hdl.handle.net/1794/29765Fear of sleep (FoS) has been posited to develop following trauma exposure and significantly contribute to the maintenance of insomnia symptoms. While FoS has been operationalized within the Fear of Sleep Inventory - Short Form (FoSI-SF), preliminary examinations of the measure have yielded diverging factor structures. Experience avoidance (EA), a trait-based measure of avoidance implicated in PTSD and insomnia symptomatology, is thought to be conceptually akin to FoS and may be an important foil to clarify the unique contributions of the construct in trauma-induced insomnia. In the present study, the psychometric properties of the FoSI-SF were evaluated in a population of college students (N = 197), including the underlying factor structure, convergent validity with EA as well as discriminant validity with sleep hygiene, another sleep-related process implicated in insomnia. A conceptual model of FoS was investigated within a subsetted sample (n = 50) that had clinically-significant PTSD and sub-threshold insomnia symptoms. An exploratory factor analysis revealed the following three-factor structure: (1) fear of loss of control and/or vulnerability (FoSI-V); (2) fear of darkness (FoSI-D); and (3) fear of re-experiencing traumatic nightmares (FoSI-N). The FoSI-SF was found to have convergent validity with EA, but did not display discriminant validity with sleep hygiene. The FoSI-V and FoSI-N were significantly predicted by trauma-related hypervigilance and nightmares, respectively. Analyses indicated that FoS was a more robust predictor of PTSD and insomnia symptom severity than EA. Theoretical implications of the findings were discussed to guide future research into the role of FoS in trauma-induced insomnia.en-USAll Rights Reserved.Acceptance and commitment therapy (ACT)Experiential avoidanceFear of sleepInsomniaPTSDElectronic Thesis or Dissertation