児童期の問題行動から青年期の心理的苦痛への発達経路：仲間関係の問題を媒介とした構造方程式モデリングアプローチ

The developmental pathways linking early conduct problems (CP) to later psychological distress (PSYD) remains insufficiently understood, particularly mediating role of peer problems (PP). This study examines how CP influence adolescent PSYD directly and indirectly through PP using longitudinal data from an Australian cohort.

Data were drawn from Waves 6-8 (ages 10-15) and Wave 9C2 (ages 17-18) of the Longitudinal Study of Australian Children (LSAC), including 1850 participants with complete data. CP and PP were assessed using the Strengths and Difficulties Questionnaire (SDQ), while PSYD was measured via the Kessler PSYD Scale (K10). Structural Equation Modelling (SEM) with Weighted Least Squares Mean and Variance Adjusted (WLSMV) estimation tested direct and indirect pathways, with PP as a mediator.

Adolescents with persistent or severe CP and PP were more likely to report severe PSYD at ages 17-18. SEM showed that PP significantly mediated the relationship between CP and PSYD, with direct effects of CP largely nonsignificant. The strongest indirect effect was observed for severe CP at Wave 8 (β̂ = 0.147, p = 0.004), followed by borderline CP at Wave 8 (β̂ = 0.107, p = 0.006), severe CP at Wave 7 (β̂ = 0.094, p = 0.004), and borderline CP at Wave 6 (β̂ = 0.027, p = 0.006). PP also showed strong temporal stability across waves.

Findings underscore the role of PP in the developmental trajectory from early CP to later PSYD, highlighting the need for early intervention targeting behavioural and peer-related difficulties.