Co-occurring trajectories of internalizing and externalizing problems from grades 1 to 12: Longitudinal associations with teacher-child relationship quality and academic performance.

This investigation examined patterns of codeveloping internalizing and externalizing problems from early childhood through adolescence (i.e., Grades 1 to 12). Subgroups of children with heterogeneous developmental trajectories (i.e., pure and co-occurring internalizing and externalizing problems) were identified and their long-term associations with teacher-child relationship quality and academic (math and reading) performance were assessed....