DS is on medication that wears off each day about 4pm so he is tired and irritable 4-6pm, then after that he gets no benefits from the medication as it seems to be out of his system. He feels great on medication every day until 4pm and wants to feel like that all the time. Do some people have medication that lasts into the evening or is the fear it will prevent sleep? He is in 6th form so evenings are important either for potential study or for not doing impulsive things when out.