A 14-year-old boy with attention deficit hyperactivity disorder (ADHD) is seen in a child and adolescent mental health services clinic. He has been on immediate-release methylphenidate for the past six years, and is currently taking 10 mg methylphenidate three times per day. His symptoms are well controlled, and there are no concerns either at home or school. He has a short stature, and is also on growth hormone injection treatment under the care of a consultant paediatrician. He is one of the country’s finest judo players and represents the English junior team for national and international competitions.