The Roles of Intrusive Visual Imagery and Verbal Thoughts in Pre-Sleep Arousal of Patients with Insomnia Disorder: A Path Model

Abstract

Purpose Researchers have proposed that multiple factors such as hyperarousal, conditioning, worrying, or cortical arousal play roles in the predisposition to, initiation, and perpetuation of insomnia disorder. Previously, only a few studies investigated the differential effects of intrusive visual imagery (IVI) and intrusive verbal thoughts (IVT) on pre-sleep arousal or insomnia severity. The aim of the current cross-sectional study was to examine these effects as well as the moderator role of visual imagery ability (VIA) on the relationship between IVI and pre-sleep arousal.Methods A path model comprising the variables of IVI, IVT, pre-sleep arousal, and insomnia severity was tested with 166 of 1444 participants (M-age = 25.5, SD = 5.26) who were identified as having insomnia disorder based on a 12-question form corresponding to DSM-5 criteria for insomnia disorder and Insomnia Severity Index scores (>= 8). The moderator role of VIA on the relationship between IVI and pre-sleep arousal was evaluated with a moderation analysis.Results It was found that IVI (beta = 0.44, p < .001), but not IVT (beta = 0.15, p = .12), significantly predicted pre-sleep arousal and pre-sleep arousal (beta = 0.44, p < .001) significantly predicted insomnia severity. In addition, the indirect effect of IVI via pre-sleep arousal (IE = 0.19, p < .001) on insomnia severity was significant. Finally, the moderator role of VIA on the relationship between IVI and pre-sleep arousal (p = .07) was not significant.Conclusions IVI may play a more important role in insomnia disorder than IVT. Interventions targeting pre-sleep visual imagery can help poor sleepers alleviate insomnia severity.