The stability and persistence of symptoms in childhood-onset ADHD

The course of childhood-onset attention deficit hyperactivity disorder (ADHD) varies across individuals; some will experience persistent symptoms while others' symptoms fluctuate or remit. We describe the longitudinal course of ADHD symptoms and associated clinical characteristics in adolescents with childhood-onset ADHD. Participants (aged 6-12 at baseline) from the Longitudinal Assessment of Manic Symptoms (LAMS) study who met DSM criteria for ADHD prior to age 12 were evaluated annually with the Kiddie Schedule for Affective Disorders and Schizophrenia for eight years. At each timepoint, participants were categorized as meeting ADHD criteria, subthreshold criteria, or not having ADHD. Stability of course was defined by whether participants experienced consistent ADHD symptoms, fluctuating symptoms, or remission. The persistence of the symptoms was defined by symptom status at the final two follow-ups (stable ADHD, stable remission, stable partial remission, unstable). Of 685 baseline participants, 431 had childhood-onset ADHD and at least two follow-ups. Half had a consistent course of ADHD, nearly 40% had a remitting course, and the remaining participants had a fluctuating course. More than half of participants met criteria for ADHD at the end of their participation; about 30% demonstrated stable full remission, 15% had unstable symptoms, and one had stable partial remission. Participants with a persistent course and stable ADHD outcome reported the highest number of symptoms and were most impaired. This work builds on earlier studies that describe fluctuating symptoms in young people with childhood-onset ADHD. Results emphasize the importance of ongoing monitoring and detailed assessment of factors likely to influence course and outcome to help young people with childhood-onset ADHD.