Loneliness, Internalizing and Externalizing Problems, and Suicidal Ideation Among Chinese Adolescents: A Longitudinal Mediation Analysis.

Purpose: Research indicates that loneliness and emotional and behavioral problems increase the risk of suicidal ideation in adolescents, but less is known about the distinct contributions of these problems. This study aimed to distinguish the pathways through which loneliness, internalizing problems, and externalizing problems contribute to suicidal ideation in Chinese adolescents.

Methods: We did a longitudinal mediation analysis with data collected at 3 time points (2021.05, 2021.10, and 2022.05) from 28 Taizhou high schools. Loneliness and suicidal ideation were assessed using the UCLA 3-Item Loneliness Scale and one suicide item from the Children's Depression Inventory, respectively. The Strength and Difficulties Questionnaire assessed internalizing (emotional and peer problems) and externalizing problems (conduct and hyperactivity problems). Structural equation modeling was used to construct complete longitudinal path models.

Results: Using data from 2,190 adolescents in junior and senior high schools, we found that loneliness, internalizing problems, and externalizing problems separately contributed to subsequent higher levels of suicidal ideation. Most notably, loneliness predicted worse subsequent internalizing problems (β = 0.279, p < .001) and externalizing problems (β = 0.159, p < .001), which in turn predicted more severe suicidal ideation (β = 0.019, p < .001; β = 0.018, p < .001). Loneliness also partially mediated the association between internalizing or externalizing problems and suicidal ideation.

Discussion: Loneliness, internalizing problems, and externalizing problems were strongly intertwined with suicidal ideation in adolescents. Public health initiatives could reduce loneliness and emotional and behavioral problems by implementing multifaceted interventions, thereby breaking the vicious circle and protecting against the development of suicidal ideation.