[Methylphenidate].

Methylphenidate enhances dopaminergic neurotransmission in the central nervous system. Methylphenidate improves social functions as well as clinical symptoms of patients suffered of narcolepsy and attention deficit hyperactivity disorder (ADHD), though it has the potential of abuse. It is reported that approximately 4% of older teens and emerging adults in the US annually misusing methylphenidate. Non-medical/illegal use of methylphenidate causes many consequences including addiction, negative reactions and medical complications. Growing number of illegal trades of methylphenidate and medical complications caused by misuse of methylphenidate urged Japanese government to introduce regulations limiting access to prescribed methylphenidate in 2008. Clinicians should be cautious about prescribing methylphenidate, especially patients with complaint of excessive daytime sleepiness.