Fluctuating course of attention-deficit/hyperactivity disorder across development: Multifactorial influences

Attention-deficit/hyperactivity disorder (ADHD) is increasingly conceptualized as a dynamic neurodevelopmental condition, marked by fluctuating symptom trajectories across development rather than the traditional static patterns of persistence or remission. This review synthesizes empirical evidence on the varied trajectories of ADHD symptoms-including late-onset, partial remission, and recurrent fluctuation patterns-and underscores their clinical significance in long-term functioning. We adopt a multifactorial framework to explore how genetic, environmental, and gene–environment interactions contribute to the emergence and evolution of ADHD symptoms over time. In addition, we consider how medication-related variables-particularly tolerance and adherence-may influence symptom fluctuation. Characterizing these developmental dynamics offers critical guidance for designing flexible, personalized interventions that align with individual trajectories and transitional vulnerabilities.