ORIGINAL CONTRIBUTION Continuity in features of anxiety and attention deficit/ hyperactivity disorder in young preschool children

Abstract Anxiety disorders and attention deficit/hyper-activity disorder (ADHD) develop before school age, but little is known about early developmental pathways. Here we test two hypotheses: first, that early signs of anxiety and ADHD at 18 months predict symptoms of anxiety and ADHD at age 3 years; second, that emotional dysregu-lation at 18 months predicts the outcome of co-occurring anxiety and ADHD at age 3 years. The study was part of the prospective Norwegian Mother and Child Cohort Study (MoBa) at the Norwegian Institute of Public Health. The 628 participants were clinically assessed at 3 years. Questionnaire data collected at 18 months were catego-rized into early behavioural scales of anxiety, ADHD, and emotional dysregulation. We investigated continuity in features of anxiety and ADHD from 18 months to 3 years of age through logistic regression analyses. Anxiety symptoms at 3 years were predicted by early signs of anxiety (Odds ratio (OR) = 1.41, CI = 1.15–1.73) and emotional dysregulation (OR = 1.33, CI = 1.15–1.54). ADHD symptoms at 3 years were predicted by early signs of ADHD (OR = 1.51, CI = 1.30–1.76) and emotional dysregulation (OR = 1.31, CI = 1.13–1.51). Co-occurring anxiety and ADHD symp-toms at 3 years were predicted by early signs of anxiety (OR = 1.43, CI = 1.13–1.84), ADHD (OR = 1.30, CI = 1.11–1.54), and emotional dysregulation (OR = 1.34, CI = 1.13–1.58). We conclude that there were modest continuities in features of anxiety and ADHD through early preschool years, while emotional dysregu-lation at age 18 months was associated with symptoms of anxiety, ADHD, and co-occurring anxiety and ADHD at age 3 years