Longitudinal Associations Between Depression, Suicidal Ideation, and Lack of Certainty in Control among Adolescents: Disaggregation of Within-Person and Between-Person Effects

Purpose: Depression and suicidal ideation (SI) are common in adolescents. However, the relation between the two is unclear. According to the cognitive model of suicidal behavior and learned helplessness theory, lack of certainty in control (LCC), referring to individuals' deficiency in predictability, certainty, and control of life, may be an important factor linking the two. Thus, the current study aimed to investigate the temporal relation between depression and SI in adolescents and to assess the mediating role of LCC in this relation. Methods: A three-wave survey was carried out at intervals of 1 and 1.5 years among 516 adolescents at several middle schools in Sichuan Province, China. The random-intercept cross-lagged panel model was used to examine the temporal relations between depression, SI, and LCC among adolescents, which can effectively distinguish between-person and within-person differences. Results: The results revealed that depression, SI, and LCC had positive intercorrelations at the between-person level. At the within-person level, early depression predicted subsequent depression and SI via LCC among adolescents. Additionally, early LCC promoted later SI through depression. Discussion: These findings highlight the mediating role of LCC, clarify the temporal relation between depression and SI, and provide theoretical support for interventions to address depression and suicide. (c) 2024 Society for Adolescent Health and Medicine. All rights reserved.