Joint developmental trajectories of internalizing and externalizing problems from mid-childhood to late adolescence and childhood risk factors: Findings from a prospective pre-birth cohort.

There is limited evidence on heterogenous co-developmental trajectories of internalizing (INT) and externalizing (EXT) problems from childhood to adolescence and predictors of these joint trajectories. We utilized longitudinal data from Raine Study participants ( = 2393) to identify these joint trajectories from 5 to 17 years using parallel-process latent class growth analysis and analyze childhood individual and family risk factors predicting these joint trajectories using multinomial logistic regression. Five trajectory classes were identified: (Low-INT/Low-EXT, 29%), (Moderate-EXT/Low-INT, 26.5%), (Moderate High-INT/Low-EXT, 17.5%), (High-INT/High-EXT, 17%), (Very High-EXT/High-INT, 10%). Children classified in and trajectories (27% of the sample) exhibited clinically meaningful co-occurring problem behaviors and experienced more adverse childhood risk-factors than other three trajectories. Compared with : parental marital problems, low family income, and absent father predicted and trajectories; maternal mental health problems commonly predicted , and trajectories; male sex and parental tobacco-smoking uniquely predicted membership; other substance smoking uniquely predicted membership; speech difficulty uniquely predicted membership; child's temper-tantrums predicted all four trajectories, with increased odds ratios for (OR = 8.95) and (OR = 6.07). Finding two co-occurring trajectories emphasizes the importance of early childhood interventions addressing comorbidity.