These practice parameters pertain to the treatment of hypersomnias of central origin. They serve as both an update of previous practice parameters for the therapy of narcolepsy and as the first practice parameters to address treatment of other hypersomnias of central origin. They are based on evidence analyzed in the accompanying review paper. The specific disorders addressed by these parameters are narcolepsy (with cataplexy, without cataplexy, due to medical condition and unspecified), idiopathic hypersomnia (with long sleep time and without long sleep time), recurrent hypersomnia and hypersomnia due to medical condition. Successful treatment of hypersomnia of central origin requires an accurate diagnosis, individual tailoring of therapy to produce the fullest possible return of normal function, and regular follow-up to monitor response to treatment. Modafinil, sodium oxybate, amphetamine, methamphetamine, dextroamphetamine, methylphenidate, and selegiline are effective treatments for excessive sleepiness associated with narcolepsy, while tricyclic antidepressants and fluoxetine are effective treatments for cataplexy, sleep paralysis, and hypnagogic hallucinations; but the quality of published clinical evidence supporting them varies. Scheduled naps can be beneficial to combat sleepiness in narcolepsy patients. Based on available evidence, modafinil is an effective therapy for sleepiness due to idiopathic hypersomnia, Parkinson's disease, myotonic dystrophy, and multiple sclerosis. Based on evidence and/or long history of use in the therapy of narcolepsy committee consensus was that modafinil, amphetamine, methamphetamine, dextroamphetamine, and methylphenidate are reasonable options for the therapy of hypersomnias of central origin.