ADHD at age 7 and functional impairments at age 10

Abstract

Background and Objectives Attention-Deficit/Hyperactivity Disorder (ADHD) cohort studies have typically involved clinical samples, and have usually recruited children across wide age ranges, limiting generalizability across complexity and developmental stage. We compared academic, emotional-behavioral and social functioning at age 10, and predictors of outcomes, in a nonreferred cohort of children recruited at age 7, between full syndrome (FS) ADHD, subthreshold (ST) ADHD and non-ADHD controls. Methods This was a prospective, cohort study with a 3 year follow-up period. Children were recruited from 43 socio-economically diverse schools in Melbourne, Australia. Multi-informant outcomes at age 10 were academic functioning (Wide Range Achievement Test-4; Social Skills Improvement System), emotional-behavioral functioning (Strengths and Difficulties Questionnaire (SDQ) Total)) and social functioning (SDQ Peer Problems). Outcomes were compared across the groups using adjusted random effects linear regression analyses. Results 477 children (62% male) were recruited at mean (SD) age 7.3 years (0.4). There were 179 FS participants, 86 ST and 212 controls. Sample retention was 78.2% at 3-year follow-up. Both the FS and ST groups were functioning worse than controls on almost all outcome measures. The best predictors of outcome for children with ADHD were working memory (academic outcome, p<0.001), ADHD symptom severity (emotional-behavioral outcome, parent: p <0.001, teacher: p<0.01), and autism spectrum disorder symptoms (emotional-behavioral outcome, parent p=0.003; social outcome, parent p=0.001). Conclusions Children with FS and ST ADHD at age 7 experience persisting functional impairments across domains at age 10. The predictors identified at age 7 present potential targets for intervention to ameliorate impairments.