The relationship between alcohol and cannabis use with nonsuicidal self-injury among adolescent inpatients: Examining the 90 days prior to psychiatric hospitalization

Background: This study examined the trajectories of alcohol use, cannabis use, suicide planning (SP), and non-suicidal self-injury (NSSI) prior to hospitalization and examined the role of alcohol and cannabis use, independently and jointly, in predicting NSSI on a daily level and over time. Methods: Participants included 71 adolescents hospitalized for suicide risk (75% female; 25% male; M-age = 15.79). All participants drank alcohol at least once in the prior 90-days. We conducted mixed effect models to assess the trajectories of alcohol use, cannabis use, and NSSI over the 90-days prior hospitalization. To test the effect of SP, alcohol use, and cannabis use on NSSI, we conducted logistic random effect models, while controlling for demographics. Results: SP (OR = 4.47, p < 0.001) and suicide ideation (SI) (OR = 10.09, p < 0.001) significantly increased the odds of engaging in NSSI. Neither cannabis nor alcohol use independently predicted the odds of engaging in NSSI, however, the co-occurrence of alcohol and cannabis use increased the odds of engaging in NSSI on a given day (OR = 30.5, p < 0.05). Conclusions: Study findings extend current knowledge about the longitudinal and day-to-day relationships between alcohol and cannabis use and NSSI. Results underscore the importance of developing interventions that address polysubstance use among suicidal adolescents engaging in NSSI.

Automated summary

The study found that suicide planning and suicide ideation significantly increased the likelihood of adolescents engaging in non-suicidal self-injury. The co-occurrence of alcohol and cannabis use also increased the odds of self-injury on specific days.