(PS9-41) The Role of Medication Use in the Indirect Relationship Between Insomnia, Aspects of Impulsivity, and Suicidal Ideation

     Sleep disturbances are consistently associated with an increased risk for suicidal behavior (Harris et al., 2020). Insomnia—difficulties in falling, staying asleep or waking up too early — has been linked to increases of suicidal ideation (Woznica et al., 2015). Additionally, medication use for insomnia has been associated with suicidal ideation and attempts (Tubbs et al., 2021), while non-medical use of medication has been linked to increased impulsivity (Grant et al., 2018).  Impulsivity is reportedly associated with suicidal behavior through many studies (Bruno et al., 2023). However, results are mixed due to inconsistencies in conceptualization and measurement (Anestis et al., 2014). This study examined the indirect effect of the combined sub-types of impulsivity on the relationship between insomnia and suicidal ideation with the presence/absence of medication use as a moderator.

     Participants (n = 766) with current SI and/or a lifetime history of a suicide attempt s were recruited online from community/university settings (Mage=23.75 years; 60.8% White, 53.1% cisgender women, 58.1% heterosexual, 57.1% single/never married). Measures included were the Insomnia Severity Index (ISI), the Urgency, Premeditation, Perseverance, and Sensation Seeking Impulsive Behavior Scale (UPPS), and a question on the use of medication for pain, sleep, depression, anxiety, or stress. In a moderated mediation model estimated using the PROCESS macro, we examined whether impulsivity accounted for the relationship between insomnia and suicidal ideation and if this indirect effect differs in strength by medication use.

     Results indicated that aspects of impulsivity accounted for the relationship between insomnia and SI among participants who were currently using psychotropic medications (B = .04, SE = .02, 95% CI [.00, .08]; (B = .04, SE = .02, 95% CI [.01, .10]). However, the strength of this indirect effect was not moderated by medication use (B = -.01, SE = .03, 95% CI [-.07, .05]). Moreover, medication use did not moderate the significant negative relationship between insomnia and impulsivity (B = -.06, SE = .10, p = .571, 95% CI [-.26, .15]), nor the significant negative relationship  between impulsivity and SI (B = .06, SE = .08, p = .400, 95% CI [-.09, .21]), suggesting that effects related to impulsivity do not vary in strength depending on whether one takes medications or not. Notably, medication use did moderate the relationship between insomnia and SI (B = .47, SE = .08, p < .001, 95% CI [.26, .70]), with a stronger association among those who reported medication use (B = .88, SE = .07, p < .001) compared to those who did not (B = .40, SE = .08, p < .001).

     Although greater levels of insomnia were associated with increased SI, those with insomnia who used medication were significantly more likely to experience SI. Suggesting that those with more severe insomnia symptoms may use medication more than those without such symptoms. Further, the inverse relationship between impulsivity and SI runs contrary to previous literature and requires further research with distinction between the sub-types used. This underscores the need for suicide prevention efforts that emphasize comprehensive risk assessments, particularly for individuals taking medication.