Dual-Factor Model of Mental Health: Latent Growth Curve Analyses of Psychosocial 
Outcomes Among Japanese Adolescents

2. Faculty of Human Studies, Shirayuri University, Tokyo, Japan

Abstract: Objectives: The dual-factor model was proposed as a comprehensive framework to assess and improve mental health outcomes. This model has been applied to the health of youth in the West; however, its validity has not been verified in other cultures. The present three-wave longitudinal study evaluates the utility of this model in understanding the trajectories of psychosocial functioning for high-school students in Japan. Methods: We assessed life satisfaction, behavioral problems, and psychosocial adjustment of a sample of 242 high-school students using self-report instruments every year, for three years. Students were classified into one of four distinct groups based on high/low psychopathology and high/low life satisfaction measured at the first year of high school. Using multigroup latent growth curve analyses, we explored whether the groups showed distinct trajectories in psychosocial outcomes across a three-year period. Results: The dual-factor model was supported through the identification of four distinctive mental health groups at the initial measurement. The group differences were further observed in different trajectories of psychosocial outcomes: The family relationships scores for symptomatic but content and troubled groups declined over time, and troubled youths reported a more negative trend than the other groups. In addition, self-esteem scores tended to increase over time for the vulnerable youths, and peer relationships for the troubled youths showed a negative trend. Conclusions: The results validated the importance of incorporating both positive and negative indicators of mental health to fully understand the different trajectories of psychosocial functioning and to provide effective intervention programs for Japanese youth.