ADHD symptoms and subtypes: relationship between childhood and adolescent symptoms.

OBJECTIVE To study attention-deficit/hyperactivity disorder (ADHD) symptoms and DSM-IV subtypes in childhood and adolescence. METHOD A total of 457 adolescents ages 16 to 18 years from the Northern Finland Birth Cohort 1986 participated in an epidemiological survey for ADHD. After assessment with a diagnostic interview those with current or childhood ADHD were classified using DSM-IV criteria. Childhood diagnosis of ADHD was set according to retrospective recall. The characteristics and relationships in ADHD symptomatology in childhood and adolescence were studied in relation to behavioral problems and parental history of attentional problems. RESULTS ADHD was reported more commonly in childhood than in adolescence and variations in subtype classification occurred. Those with childhood and adolescent diagnosis had endorsed specific inattentive symptoms more commonly, had greater comorbid major depression and/or oppositional defiant disorder, and had fathers with more reported attentional problems than those with only childhood diagnosis. In childhood, ADHD subtypes differed along symptom severity, but by adolescence these differences were no longer significant. CONCLUSIONS The persistence of ADHD from childhood to adolescence may be common. Specific inattentive symptoms, certain psychiatric comorbidity, and family history of attention problems (fathers specifically) contribute to the risk of persistent ADHD. ADHD subtype differences reflect symptom severity differences in childhood that are negligible by adolescence.