Normal sleep begins with NREM sleep during which the brain waves begin to slow. Patients with narcolepsy fall immediately into REM sleep without going through the normal stages. There is a neuropeptide called hypocretin (hi-po-KREET-in) or orexin which regulates REM sleep and the ability to stay awake during the day. Scientists have discovered that people with narcolepsy have very low levels of this hormone and the cells that create it are badly damaged.
Narcolepsy affects about one out of every 2,000 people and occurs slightly more often in men than in women. It usually begins in the pre-teen years to early adulthood. Many people who have narcolepsy suffer from depression.