Do emotional difficulties and peer problems occur together from childhood to adolescence? The case of children with a history of developmental language disorder (DLD).

Children and adolescents with developmental language disorder (DLD) are, overall, vulnerable to difficulties in emotional adjustment and in peer relations. However, previous research has shown that different subgroups follow different trajectories in respect to the quality of peer relations. Less is known about the trajectories of emotional development. We consider here the possibility that development in these two domains is interrelated: that is, the trajectories of emotional and peer problems will proceed in parallel. We conducted longitudinal joint trajectories analyses of emotional and peer relations in a sample of young people identified as having DLD at the age of 7 years and seen at intervals up to 16 years. Potential influences on joint trajectory group membership were examined. Findings revealed five distinct joint trajectories. Emotional and peer difficulties do occur together from childhood to adolescence for just over half of the sample, but not all. The variables most clearly associated with group membership were pragmatic language ability, prosociality and parental mental health. This is the first study to examine joint longitudinal trajectories of emotional and peer difficulties in individuals with DLD. We demonstrate that development in individuals with DLD is heterogeneous and identify three key variables associated with personal and social adjustment from childhood to adolescence. Theoretical and clinical implications of these findings are discussed.