Most childhood ADHD cases do not fully remit by adulthood

The assumption that half of childhood ADHD cases remit by adulthood may be inaccurate, as symptoms fluctuate into adulthood in most cases, according to results of a multimodal treatment study published in American Journal of Psychiatry.

“Substantial scientific work has examined ADHD persistence — the extent to which children with ADHD continue to meet DSM criteria for the disorder in adolescence and adulthood,” Margaret H. Sibley, PhD, of the department of psychiatry and behavioral sciences at the University of Washington School of Medicine, and colleagues wrote. “However, less research has investigated remission (loss of symptoms and impairment), recurrence and recovery (sustained remission over time). Most longitudinal ADHD studies simply define remission as ‘failing to meet DSM criteria,’ with few attempts to identify or define distinct subtypes and patterns of remission.”

According to the researchers, describing common trajectories of ADHD remission, recurrence and recovery is vital to informing provider, patient and family treatment decisions. Prior research showed an estimated childhood ADHD remittance rate of 50% by adulthood; however, researchers often derived this conclusion based on single endpoints, which to not account for longitudinal patterns of ADHD expression.

In the current study, Sibley and colleagues sought to examine how often and significantly children with ADHD experienced recovery, as well as differing remission patterns, by adulthood. They analyzed data of 558 children with ADHD who participated in the Multimodal Treatment Study of ADHD, during which they were assessed eight times over follow-ups that ranged from 2 years (mean age, 10.44 years) to 16 years (mean age, 25.12 years) after baseline. They identified participants who had fully remitted, partially remitted and persistent ADHD at each time point according to parent, teacher and self-reports of ADHD symptoms and impairment, treatment utilization and substance use and mental disorders. Further, the researchers pinpointed longitudinal remission and persistence patterns that accounted for context and timing.

Results showed approximately 30% of participants fully remitted at some point during follow-up; however, 60% had ADHD recurrence after the initial remission period. A total of 9.1% of the sample had sustained remission by study endpoint and 10.8% had stable ADHD persistence across study time points. A total of 63.8% of participants had fluctuating remission and recurrence periods over time.

“Given these findings, assessing factors that may influence symptom fluctuations (eg, environmental fit, physical health) should be central to evaluation and treatment of ADHD across the lifespan,” Sibley and colleagues wrote. “Future research should investigate malleable biological and environmental factors that trigger symptom fluctuations and might serve as targets for new classes of environmental or health interventions (eg, modifications to factors that may catalyze and maintain symptomatic periods). Based on these findings, clinicians can communicate to families that most adolescents and young adults with ADHD ([approximately] 90%) experience at least intermittent relief from their ADHD symptoms over time that may be modulated by personal or life circumstances.”