ADHD and ODD Symptoms in Toddlers: Common and Specific Associations with Temperament Dimensions.

The aim of this work was to study the relationship between temperament and signs of psychopathology in typically developing toddlers. More specifically, Attentional Deficit Hyperactivity Disorder (ADHD) and Oppositional Defiant Disorder (ODD) symptoms were analyzed in connection with fine-grained temperament dimensions. The sample was composed of 65 toddlers aged between 18 and 35 months. Bivariate correlations showed that higher levels of negative emotionality and approach tendencies, and lower levels of inhibitory control, were related to more ADHD and ODD manifestations. Bivariate correlations also indicated unique associations: lower levels of soothability were associated with higher ODD symptoms, whereas lower attentional focusing and low-intensity pleasure were related with higher ADHD symptoms. Additionally, regression and path analysis models indicated that ADHD was predominantly associated with attentional focusing and motor activation whereas ODD was most closely related to frustration. Our findings highlight the relevance of studying early correlates of psychopathological manifestations to identify children who could benefit from prevention and early intervention programs.