Linking oppositional behaviour trajectories to the development of depressive symptoms in childhood.

Oppositional defiant disorder in childhood is a predictor of later mood disorders. This study assessed whether groups of children can be identified by their course of co-occurring oppositional and depressive symptoms in childhood using group based trajectory modeling. Participants were a cohort of 932 4 or 5 year old offspring of women participating in the National Longitudinal Study of Youth whose symptom trajectories were modeled across ages 4-13 years. Three co-occurring trajectory groups were found: oppositional symptoms only (23%), oppositional symptoms preceding increasing depressive symptoms over time (16%) and absence of any symptoms (61%). Of all children who developed depressive symptoms, all had moderate or high levels of pre-existing oppositional symptoms. Oppositional symptoms typically precede, or co-occur with depressive symptoms in childhood.