Taylor is a 11 year-old boy brought to your office by his mother because his teachers at school reported that Taylor has trouble holding attention on tasks; he does not seem to listen when spoken to directly; he interferes with other students unnecessarily even after being warned not to do so, he fails to give close attention to details; he frequently leaves his seat to go out of the classroom; he blurts out answers before the teacher finish asking the question; he does not wait for his turn. At home, his mother noticed that he is easily distracted; he does not sit quietly at the dinner table, he stops eating one dessert and goes for another dessert, he taps his hands and feet if he has to sit in one place for more than a minute. In the physical examination, you noticed a very talkative child, not able to sit properly in one place and very fidgety. Which of the following is the first-line treatment for his disorder?