An 8-year-old boy is brought to the outpatient clinic by his mother with complaints of inattention, hyperactivity, and impulsivity at school for the past 18 months. The teacher reports difficulty in following instructions and frequent interruptions during class. The child's developmental history is unremarkable. Physical examination and basic investigations are normal. The mother denies any symptoms of ADHD in herself or the father. What is the most appropriate next step in management?