The longitudinal relationship between socioemotional difficulties and irritability in ADHD

Background: Despite higher rates of irritability and socioemotional symptoms in ADHD, consensus is lacking regarding their developmental relationship and whether it differs by ADHD status. This longitudinal study sought to evaluate how peer and emotional difficulties relate to irritability in ADHD and control groups. Methods: A community sample of 336 participants (45 % ADHD) were recruited for the Children's Attention Project. Participants completed the Affective Reactivity Index and the Strengths and Difficulties Questionnaire's emotional and peer difficulties scales at baseline (mean age 10.5 years) and 18-month follow-up. Latent Change Score models assessed how emotional and peer difficulties related to irritability at baseline and longitudinally. Results: For both groups, more severe baseline difficulties were associated with higher concurrent irritability, and reductions in emotional and peer difficulties were associated with declining irritability. Baseline emotional difficulties predicted change in irritability for the ADHD group, while baseline peer difficulties predicted change in irritability for both groups. Baseline irritability did not predict change in emotional or peer difficulties for either. The ADHD group showed elevated irritability, emotional, and peer difficulties, and stronger baseline correlation between peer difficulties and irritability. Limitations: Only two timepoints were captured, and associations with ADHD symptom severity and presentation were not investigated. Doing so may facilitate additional insights. Conclusions: Change in irritability corresponded to change in socioemotional difficulties, and was driven by earlier levels of socioemotional difficulties. ADHD exacerbated aspects of the relationship between socioemotional difficulties and irritability. Socioemotional difficulties drive irritability, so may represent targets for clinical interventions.