Early treatment response as predictor of long-term outcome in a clinical cohort of children with ADHD

This study investigates early onset of treatment response as predictor of symptomatic and functional outcome 3 years after initiation of methylphenidate (MPH) administration in a naturalistic, clinical cohort of children and adolescents with ADHD. Children were followed across an initial 12-week MPH treatment trial and after 3 years, with ratings of symptoms and impairment. Associations between a clinically significant MPH treatment response in week 3 (defined as ≥ 20% reduction in clinician-rated symptoms) and in week 12 (defined as ≥ 40% reduction), and 3-year outcome were tested in multivariate linear regression models, adjusting for sex, age, comorbidity, IQ, maternal education, parental psychiatric disorder, and baseline symptoms and function. We did not have information on treatment adherence or the nature of treatments beyond 12 weeks. 148 children, mean age 12.4 years (range 10–16 years), 77% males, participated in the follow-up. We found a significant decrease in symptom score from baseline [ M = 41.9 (SD = 13.2)] to 3-year follow-up [ M = 27.5 (SD = 12.7), p