Adolescent Substance Use Patterns and Risk for Suicidal Thoughts and Behaviors in Young Adulthood

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.

Figure 1.

Percentage of adolescents in the full sample using each substance in each grade in high school. Notes: Among the full sample of adolescents (n = 2,780), the majority (≥74%) reported not using any substances during high school. The percentage of adolescents in the full sample using tobacco, alcohol, marijuana, or other drugs once or twice during high school was as follows: 6%–7%, 8%, 7%–9%, and 3%–5%, respectively. The percentage of adolescents using these substances three or more times during high school was as follows: 10%–15%, 11%–16%, 15%–18%, and 3%–7%, respectively. Tobacco and binge drinking were measured based on past-30-day use, whereas marijuana and other drug use was measured based on use in the past 12 months.

Figure 2.

Results of latent class analysis of substance use from 10th to 12th grade. Notes: Non-/infrequent users (n = 1,976; 2A) include adolescents with a low probability of using tobacco, binge drinking, using marijuana, and using other drugs. Multiple substance users (n = 804; 2B) include adolescents with a higher probability of using all substances, particularly tobacco, alcohol, and marijuana.