Abstract
OBJECTIVE: There is strong evidence that substance use is a risk factor for suicidality. Prior studies have focused on the suicide risk associated with using individual substances, even though substance users often use more than one substance. This study investigates the association between patterns of adolescent substance use and suicidality in young adulthood. METHOD: Participants were U.S. adolescents (n = 2,111, 58.9% female, mean age = 16.31 years) from the NEXT Generation Health Study, which followed tenth graders for 7 years (2009/2010-2016) and collected data via yearly surveys. Longitudinal latent class analysis was used to identify high school patterns of substance use, and logistic regression was used to relate these patterns to risk of suicidality in young adulthood. RESULTS: We identified two groups of adolescents: "non-/infrequent users" (71%) and "multiple substance users" (29%). Multiple substance users had higher odds of making a suicide plan or attempt in young adulthood (odds ratio [OR] = 2.41, 95% CI [1.05, 5.53]), but not suicidal ideation (OR = 1.55, 95% CI [0.80, 2.99]), than non-/infrequent users, adjusting for sociodemographic factors and depressive symptoms. Multiple substance users with suicidal ideation were not more likely to progress to a later plan or attempt (OR = 1.41, 95% CI [0.41, 4.84]) than non-/infrequent users. CONCLUSIONS: Adolescents who use substances in high school are at higher risk for making a suicide plan or attempt in young adulthood. Early identification of these adolescents may help inform interventions to mitigate risk for suicidal behaviors in young adulthood.