Below is an instruction from Human. Write a response.
    ### Instruction:
    How to diagnose Narcolepsy ?
    ### Response:
    How is narcolepsy diagnosed? Narcolepsy is often diagnosed in adolescence and young adulthood, when falling asleep suddenly in school brings the problem to attention. However, for many people with narcolepsy, the disorder is not diagnosed for up to 10-15 years after symptoms first begin.
    