Attention-deficit/hyperactivity disorder persistence from childhood into young adult age: a 10-year longitudinal study.

INTRODUCTION: The aim of this study was to estimate ADHD persistence in a European clinical sample of children diagnosed with ADHD and followed prospectively for 10 years into young adulthood.

METHODS: We assessed 85 children with ADHD at baseline ( M age  = 11.6, SD = 2.1, 54% male) and re-assessed 59 at 10-year follow-up ( M age  = 21.4, SD = 2.3, 54% male). ADHD symptoms at baseline were assessed with a semi-structured clinical interview (Kiddie-Schedule for Affective Disorders and Schizophrenia/Present and lifetime version) and parent rating scales (ADHD Rating Scale IV, Child Behavior Checklist). ADHD symptoms at 10-year follow-up were assessed with a semi-structured clinical interview (MINI-Plus) and self-report scales (ADHD Self-Report Scale version 1.1 screener, Adult Self Report). Functional impairment at 10-year follow-up was assessed with the Global Assessment of Functioning scale.

RESULTS: At 10-year follow-up, 39% met ADHD symptom thresholds based on clinical evaluation using MINI-Plus or the ADHD Self-Report Scale version 1.1 screener or the Adult Self Report together with clinicians' rating of functional impairment.

CONCLUSION: ADHD persistence rates in this European clinical sample match previous estimates and indicate that a significant proportion of those diagnosed with ADHD as children still exhibit clinical levels of ADHD symptoms in adulthood.