An 8-year-old girl is referred to the psychiatry clinic by her school for evaluation of persistent inattention and poor academic performance. She is described as a "daydreamer" who frequently loses focus during lessons and forgets instructions. At home, she is quiet and compliant but struggles to complete homework without constant reminders. Her mother denies any hyperactivity or impulsivity. Developmental history is unremarkable. On assessment, she demonstrates intact attention during one-on-one conversation but shows poor sustained attention on continuous performance testing. Which subtype of ADHD is most likely, and what is a key consideration before initiating pharmacotherapy?