The trajectories of internalizing and externalizing problems from early childhood to adolescence and young adult outcome

Objectives: Trajectory studies are increasingly used to explore the developmental course of internalizing and externalizing problems. However, less is known about the adult outcome of children on different childhood trajectories. The current study explores how the trajectories of internalizing and externalizing problems from early childhood to adolescence are associated with the psychosocial wellbeing of normal population young Finnish adults (n=144). Methods: The trajectories were based on mothers’ reports of the Child Behavior Checklist evaluated at the ages of 4-5, 8-9 and 16-17 years. The young adult outcome was based on the Adult Self Report and the EuroHIS-8 Quality of life questionnaire at the age of 27 years. Results: A high or increasing trajectory of internalizing problems from early childhood to adolescence increased the risk of internalizing problems, depressive problems and avoidant personality problems at the age of 27. High trajectory of internalizing problems decreased the risk of externalizing and antisocial problems at young adulthood. A high trajectory of externalizing problems in childhood increased the risk of a wide range of emotional and behavioral problems and poorer quality of life in young adulthood. Discussion: The study suggests that especially the developmental pattern of high externalizing problems is set at an early age and increases the risk of poorer psychosocial outcome in young adulthood. Early prevention and treatment are essential.