Psychiatrymiddle twist
A 17-year-old with attention deficit hyperactivity disorder has taken immediate-release methylphenidate 10 mg at 8 am and 10 mg at 1 pm for two years, sleeping well. A fortnight ago the afternoon dose was raised to 20 mg and moved to 4 pm so that he could study for examinations. His concentration has improved but he now lies awake until 2 am and is exhausted at breakfast. He has no anxiety, takes no caffeine after midday, and his screen use and bedtime routine are unchanged. Which one of the following is the most appropriate first change to his management?