Suicidality and Latent Subgroups of Substance Use Among Korean Adolescents

Background: Suicide is the leading cause for adolescent’s death in South Korea. Although the current body of literature on suicidality and substance use are in consensus that these two variables are significantly related to one another, the issue of directionality (e.g., suicidality on substance use, substance use on suicidality) still remains debatable. Given this literature gap, the current study attempted to add more empirical evidence on the directionality of substance use and suicidality, and how each component of suicidality (e.g., suicidal ideation, suicide plan, and suicide attempt) is connected to polysubstance use of Korean adolescents. As a result, this study aims to identify substance use classes in Korean adolescents and assess the impact of suicidality in each class.

Methods: The 2022 Korea Youth Risk Behavior Survey, comprising 51,850 youths aged 12 to 18 was used for the analysis. The missing data was handled using a Full Information Maximum Likelihood approach. The Latent Class Analysis (LCA) was employed to identify subgroups of substance use, namely alcohol, traditional cigarettes, e-cigarettes, and heated tobacco products. Furthermore, the present study integrated BCH auxiliary variables (i.e., suicide ideation, suicide plan, suicide attempt) to evaluate equality across each type of latent layer. Once the classes are identified, multivariate logistic regression analysis was conducted to examine the connections between suicidality and different substance use subgroups. During these analyses, gender, school type, academic performance, and socioeconomic status were utilized as covariates.

Results: Based on the LCA, the study sample was categorized into four substance use groups: Class 1 (“Severe Polysubstance Use Group”), Class 2 (“Alcohol-Only Use Group”), Class 3 (“E-cigarette Priority Polysubstance Use Group”), and Class 4 (“Conventional Polysubstance Use Group”). Suicidal ideation (OR = 2.2), and suicide attempts (OR = 3.1) were associated with an increased likelihood of belonging to Class 1 when compared to Class 2. Furthermore, suicidal ideation (OR = 2.0), suicidal plan (OR = 1.6), and suicide attempts (OR = 2.4) were all linked to an elevated likelihood of being part of Class 3 in comparison to Class 2. In addition, experiencing suicidal ideation (OR = 2.8) was related to a higher likelihood of being included in Class 4 when compared to Class 2. Experiencing suicidal planning (OR = 2.1) was associated with an increased likelihood of belonging to Class 3 compared to Class 1.

Conclusion/Implication: As suicidality has been identified as a risk factor for Korean adolescent’s polysubstance use, an integrated intervention model should be developed to address both suicidal thoughts and/or behaviors and substance use simultaneously. At the practice level, the frontline social workers should continuously monitor the youths who were once at a risk of suicide along with their substance use patterns. Additionally, given that e-cigarette priority group was more vulnerable to suicidality than any other groups, future e-cigarette intervention program should discuss trauma and other psycho-, social-, and emotional-stressors to prevent adolescents from using e-cigarette and thinking of suicide.