Pre-trauma insomnia and posttraumatic alcohol and cannabis use in the AURORA observational cohort study of trauma survivors

Insomnia symptoms are a potential risk factor for alcohol and cannabis use, particularly in trauma-exposed populations. The initial weeks and months after trauma are a period of risk for problematic substance use, however prior research has not examined whether insomnia symptoms predict alcohol or cannabis use after trauma.

Using a large-scale, multi-site, prospective study of trauma survivors presenting to emergency departments (EDs), the current study tested direct and indirect associations between pre-trauma insomnia symptoms, two-week posttraumatic stress disorder (PTSD) symptoms, and eight-week post-trauma heavy alcohol and cannabis use and binge drinking.

Participants were recruited from 23 EDs in the United States and followed up using remote assessments.

Participants were from the AURORA study (n = 2449). A slight majority were women (63.8 %) and were an average of 37 years old. Participants were racially and ethnically diverse (50.5 % Black, 11.2 % Hispanic).

Participants completed self-report measures during their ED visit, and two- and eight-weeks post-trauma.

Pre-trauma insomnia symptoms significantly predicted eight-week post-trauma heavy alcohol and cannabis use, as well as binge drinking. Associations persisted after covarying for pre-trauma substance use, demographic variables, and trauma severity at the time of emergency care. Further, the association between pre-trauma insomnia symptoms and heavy alcohol and cannabis use at eight-weeks post-trauma was significantly mediated by two-week PTSD symptoms.

Insomnia symptoms may be an important malleable risk factor for heavy alcohol and cannabis use and binge drinking after trauma. Further research is needed to explore the effectiveness of insomnia interventions to mitigate post-trauma substance use and to better understand the complex relationships between sleep, trauma, PTSD, and substance use.