Concurrent trajectories of BMI and mental health patterns in emerging adulthood.

Affective disorders and weight status have been consistently linked in childhood and adult research, and this comorbidity has synergistic effects leading to more severe health consequences. We map the co-development of these developmental processes in the U.S. National Longitudinal Survey of Youth - 1997 (NLSY97) cohort ages 15 to 27 to inform the targeting of public health interventions. We estimate profiles of youth mental health and weight status through parallel process growth mixture modeling within a person-centered framework controlling for race/ethnicity, gender, and poverty status. Fit statistics indicate a 5-class parallel process model for the concurrent trajectories of BMI and mental health. The concurrent trajectories model reveals latent class trajectories of "stable normal weight, stable good mental health" (82.2%); "consistently obese, stable good mental health" (6.8%); "overweight becoming obese, declining mental health" (5.6%); "stable normal weight, improving mental health" (3.3%); and "morbid obesity, stable good mental health" (2.1%). The risk of developmental trajectories of poor mental health and BMI outcomes is greater for females, blacks, Hispanics, and individuals living below the poverty line. These results should help public health professionals to better target subpopulations approaching or already experiencing developmental pathways of risk for poor mental health and weight comorbidities. Multilevel investigation of lifestyle and contextual factors will foster further refinement of public health interventions.