A 17-year-old male is brought to your outpatient clinic by h…

A 17-year-old male is brought to your outpatient clinic by his parents due to escalating mood swings, risk-taking behaviors, and school refusal. He reports alternating periods of “feeling great and invincible” for several days, during which he sleeps 2–3 hours per night, spends excessive time on social media, and engages in impulsive driving. These episodes are followed by periods of low mood, irritability, and social withdrawal. He denies suicidal ideation but admits to recent marijuana use and vaping nicotine daily. His parents are concerned about his safety and request medication. Mental status exam reveals pressured speech, grandiosity, and distractibility. Urine drug screen is positive for THC. He has no prior psychiatric history and no known medical conditions. He refuses therapy but agrees to medication “if it helps him focus.” Which of the following is the most appropriate next step in managing this patient?