Although no one wants a poor night’s sleep, most of us occasionally experience sleep disruptions for familiar reasons, such as working late at night, too much caffeine, stress or inconsistent bedtime routines.
But for many others, sleep problems run much deeper as millions of people live with sleep disorders such as insomnia, restless legs syndrome, circadian rhythm disorders or sleep apnea.
Some people also suffer from rare conditions that affect not only sleep at night but also the ability to stay awake and alert during the day. One such condition is narcolepsy.
Although it is often misunderstood—and sometimes portrayed in films and television as “falling asleep without warning”—the reality of narcolepsy is far more complex. Here’s what it is, what causes it, and how it is commonly treated today.
What is narcolepsy?
Narcolepsy is a chronic neurological sleep disorder “that affects the brain’s ability to regulate sleep and wakefulness,” says Dr. Raj Dasgupta, a pulmonary and sleep specialist at Huntington Memorial Hospital in California.
He explains that the brain normally maintains clear boundaries between wakefulness, sleep, and REM sleep – the deep state most closely associated with vivid dreaming. But in people with narcolepsy, such boundaries become blurred, allowing elements of sleep to intrude into wakefulness in different ways.
“There are two types of narcolepsy, type 1 and type 2,” says Alicia Roth, a behavioral sleep medicine psychologist at the Cleveland Clinic. She explains that both types have many of the same symptoms, including excessive daytime sleepiness, sudden onset of sleep, vivid dream-like hallucinations, and sleep paralysis.
But the main difference is cataplexy – a sudden and temporary loss of muscle control. Cataplexy is common in people with type 1 narcolepsy and can be triggered by strong emotions such as laughter, excitement, surprise, or anger. During an event, a person remains awake and aware, but may fall, trip over objects, or even fall. In contrast, “people with type 2 narcolepsy do not have cataplexy,” Roth says.
Narcolepsy is relatively uncommon, estimated to affect only 1 in 2,000 people, with type 1 generally considered the more common form.
“Both types are usually diagnosed based on the patient’s detailed sleep history and a sleep test—usually an overnight sleep study followed by a daytime nap test, called a multiple sleep latency test,” says Dasgupta.
In some cases, doctors may also measure the levels of a specific brain chemical through a lumbar puncture or spinal tap. Very low levels of this chemical can help confirm type 1 narcolepsy, although Dasgupta says the test is rarely used as a first-line diagnostic tool because it is invasive.
Plus, narcolepsy is often overlooked and can take years to accurately diagnose, “because the key symptom of narcolepsy — excessive daytime sleepiness — is often attributed to stress, poor sleep, depression, sleep apnea, or a busy lifestyle,” says Dasgupta.
Meanwhile, the disorder can significantly impact daily life, making it difficult to concentrate at work or school and even safely operate any type of vehicle. Some people also experience “sleep attacks”, in which they fall asleep unexpectedly during conversation, meals, or other activities; Or they may experience anxiety, depression, social isolation, and strained relationships. “There is a strong literature to show that narcolepsy has a devastating impact on all aspects of living a good life,” says Roth.
What causes narcolepsy?
Although doctors still don’t fully understand every cause of narcolepsy, the strongest evidence points to a problem involving a brain chemical called hypocretin, also known as orexin. “This neurotransmitter helps stabilize wakefulness and suppresses inappropriate REM sleep, so its deficiency causes instability that can lead to sudden REM intrusions,” explains Dasgupta.
Most people with type 1 narcolepsy have extremely low levels of hypocretin because the brain cells that produce it have been damaged or destroyed. This damage is often the result of an autoimmune process in which the body’s immune system mistakenly attacks those cells.
In addition to autoimmune disorders, genetics may also play a role. That’s because certain genetic markers are much more common in people with narcolepsy, according to the National Institute of Neurological Disorders and Stroke, although having those genes does not guarantee that someone will develop the condition.
Infections, other immune-system stresses and, rarely, brain injuries may also contribute in genetically susceptible individuals.
How is narcolepsy treated?
Although there is currently no cure for narcolepsy, effective treatments can help many people manage their symptoms and improve their quality of life.
“Generally, narcolepsy is treated with medication,” says Roth. She explains that treatment often begins with wake-promoting medications or stimulants that help reduce excessive daytime sleepiness. She adds that other medications, including sodium oxybate and low-sodium oxybate, are sometimes taken at night to help improve sleep quality, reduce daytime sleepiness, and control cataplexy. Some antidepressants may also be prescribed to help manage cataplexy, sleep paralysis, and hallucinations.
But medication alone is usually not enough. “Medication is most effective when combined with behavioral strategies like scheduled naps, a consistent sleep routine, and a safety plan,” says Dasgupta.
In fact, maintaining a regular sleep schedule, exercising frequently, avoiding sleep deprivation, and limiting alcohol intake can all help with treatment. Many people with narcolepsy also benefit from short, scheduled naps during the day, which temporarily improve alertness and reduce sleepiness.
Although many things can cause daytime fatigue, there are some signs that could point to something more serious. “If someone feels sleepy every day despite getting enough sleep, falls asleep in unsafe or inappropriate situations, or is unable to wake up during normal activities, then you may be dealing with a serious problem like narcolepsy,” says Dasgupta. “Other red flags include sleep paralysis, intense hallucinations while falling asleep or waking up, or sudden muscle weakness due to laughter or intense emotions.”
While narcolepsy can be life-altering, Dasgupta says early diagnosis and appropriate treatment can “help many people gain control of their symptoms and live full, productive lives.”