title: Investigating the Interaction Between Sleep Symptoms of Arousal and Acquired Capability in Predicting Suicidality.
abstract: Heightened arousal significantly interacts with acquired capability to predict suicidality. We explore this interaction with insomnia and nightmares independently of waking state arousal symptoms, and test predictions of the Interpersonal Theory of Suicide (IPTS) and Escape Theory in relation to these sleep arousal symptoms. Findings from our e-survey (n = 540) supported the IPTS over models of Suicide as Escape. Sleep-specific measurements of arousal (insomnia and nightmares) showed no main effect, yet interacted with acquired capability to predict increased suicidality. The explained variance in suicidality by the interaction (1%-2%) using sleep-specific measures was comparable to variance explained by interactions previously reported in the literature using measurements composed of a mix of waking and sleep state arousal symptoms. Similarly, when entrapment (inability to escape) was included in models, main effects of sleep symptoms arousal were not detected yet interacted with entrapment to predict suicidality. We discuss findings in relation to treatment options suggesting that sleep-specific interventions be considered for the long-term management of at-risk individuals.
authors.affiliation: Department of Psychology, University of Chester, Chester, UK.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Hochard
authors.affiliation: Department of Psychology, Nottingham Trent University, Nottingham, UK.
authors.forename: Nadja
authors.initials: N
authors.lastname: Heym
authors.affiliation: Department of Psychology, University of Nottingham, Nottingham, UK.
authors.forename: Ellen
authors.initials: E
authors.lastname: Townsend
mesh_terms: D001143:Arousal / Q000502:physiology*; D004325:Dreams / Q000523:psychology; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D012307:Risk Factors; D012890:Sleep / Q000502:physiology*; D007319:Sleep Initiation and Maintenance Disorders / Q000523:psychology; D059020:Suicidal Ideation; D013405:Suicide / Q000523:psychology*