Association of Cigarette Type Initially Smoked With Suicidal Behaviors Among Adolescents in Korea From 2015 to 2018.

Importance: Assessment of whether past electronic cigarette (e-cigarette) use or initiating smoking with e-cigarettes is associated with suicidal behaviors among adolescents is needed to inform future research and public health interventions. Objective: To evaluate the association between starting smoking with e-cigarettes or conventional cigarettes and suicidal behaviors among Korean adolescents. Design, Setting, and Participants: This cross-sectional study analyzed data on adolescents in grades 7 through 12 who participated in the nationwide Korea Youth Risk Behavior Web-Based Survey between 2015 and 2018. Exposures: Type of cigarette initially smoked: electronic or conventional. Main Outcomes and Measures: Multiple logistic regression analysis was performed to examine the association between initial cigarette type and suicidal behaviors, including suicidal ideation and suicide planning and attempts. All participants completed questionnaires about their history of suicidal behavior and were categorized into groups according to the type of cigarette used at initiation of smoking and any subsequent change (or lack of change) in the type of cigarette used. Results: A total of 255 887 Korean adolescents (51.2% male; mean (SD) age, 15.0 [1.8] years) were included in the primary analysis. Among 131 094 male adolescents, 3310 boys (2.5%) initially used e-cigarettes and 27 368 boys (20.9%) initially used conventional cigarettes. Among 124 793 female adolescents, 952 girls (0.8%) initially used e-cigarettes and 9296 girls (7.4%) initially used conventional cigarettes. Of those who initially used e-cigarettes, 178 of 3310 boys (5.4%) and 134 of 952 girls (14.1%) attempted suicide. Of those who initially used conventional cigarettes, 946 of 27 368 boys (3.5%) and 911 of 9296 girls (9.8%) attempted suicide. Adolescents who initially used e-cigarettes had a higher risk of suicidal behaviors, including suicide planning (boys: adjusted odds ratio [AOR], 1.63 [95% CI, 1.40-1.89]; P < .001; girls: AOR, 1.55 [95% CI, 1.23-1.95]; P < .001) and suicide attempts (boys: AOR, 1.55 [95% CI, 1.28-1.87]; P < .001; girls, AOR, 1.64 [95% CI, 1.29-2.10]; P < .001) compared with those who initially used conventional cigarettes. Changing from e-cigarettes to conventional cigarettes was associated with a higher risk of suicide attempts among both boys (AOR, 1.89; 95% CI, 1.39-2.57; P < .001) and girls (AOR, 2.36; 95% CI, 1.53-3.64; P < .001) compared with changing from conventional cigarettes to e-cigarettes. Conclusions and Relevance: In this study, the initial use of e-cigarettes vs conventional cigarettes was associated with suicidal behaviors among adolescents. In future research on the association of e-cigarette use with adolescent mental health and interventions for suicide prevention, the type of cigarette initially used and changing the cigarette type should be considered.