Objective: To explore age-of-onset criterion for the diagnosis of attention-deficit hyperactivity disorder (ADHD) in a school sample of young Brazilian adolescents.
Methods: 191 students aged 12 to 14 years were evaluated using DSM-IV ADHD criteria, measures of ADHD symptoms and global impairment.
Results: Both adolescents with ADHD (n = 30) and adolescents who fulfilled all DSM-IV ADHD criteria, except age of onset of impairment criterion (ADHD w/o age-of-onset, n = 27) had significantly higher scores on Attention Problems, Delinquent and Aggressive Behavior scales of the Child Behavior Checklist (CBCL) and lower scores on the Child Global Assessment scale (CGAS) than non-ADHD adolescents (n = 134). Adolescents with ADHD and youths with ADHD w/o age-of-onset did not differ significantly in any measure assessed.
Conclusion: These results concur with recent literature proposing revision of the age-of-onset criterion for the diagnosis of ADHD.