Some people with narcolepsy may be able to drive safely, especially if they drive when well-rested and stick to short trips.

Narcolepsy is a sleep disorder that affects your sleep-wake cycle. It’s characterized by overwhelming drowsiness during the day and difficulty staying awake for extended periods.

Many people with narcolepsy also experience cataplexy. This is a sudden loss of muscle control that can happen without warning.

Most people with narcolepsy are legally allowed to drive within the United States. However, according to 2022 statistics, they’re at higher risk of motor vehicle collisions than people without narcolepsy.

Keep reading to learn more about driving with narcolepsy, including the risks and safety tips.

Most people with narcolepsy can legally drive in the United States. However, it may not always be safe to do so. Regulations may vary from state to state.

In one 2020 study, people with narcolepsy reported more sleep-related collisions than people with other sleep disorders. The same study found that they were three to four times more likely to report an accident due to sleepiness than somebody in the general population.

According to the Narcolepsy Network (NN), most states rely on a voluntary process to determine whether a person is medically able to drive. Some states allow medical professionals or family members to contact the state department of motor vehicles with concerns.

California and Pennsylvania have the strictest laws for driving with narcolepsy. It’s mandatory for medical professionals in these states to report any condition that may impair a person’s ability to operate a motor vehicle. This includes narcolepsy.

In 2010, the Federal Motor Carrier Safety Administration’s Medical Review Board concluded that even people receiving proper treatment for narcolepsy are atypically sleepy in the daytime. They recommended that all people with narcolepsy should be ineligible for driver’s licenses.

A 2019 study of more than 1,300 people in Taiwan suggested that the risk of hospitalization for motor vehicle accident injuries was much higher in participants with narcolepsy than in those who did not have a narcolepsy diagnosis.

People with narcolepsy are at a high risk of drowsy driving. At least one 2020 study found that more than a third of participants with narcolepsy report an accident due to drowsiness. Excessive drowsiness can lead to inattention or to falling asleep behind the wheel.

In the same 2020 study, researchers found that 66 percent of participants with narcolepsy reported falling asleep while driving, 29 percent experienced cataplexy while driving, and 12 percent experienced sleep paralysis while driving.

Cataplexy is characterized by a sudden limpness or weakness of your muscles. Cataplexy can cause mild symptoms, such as eyelid drooping, but can also cause complete loss of bodily control. It’s often triggered by strong emotions.

Sleep paralysis is when you’re temporarily unable to move when waking or falling asleep.

Medications can help reduce sleepiness in people with narcolepsy. But even with medication, people with narcolepsy rarely have the same ability to stay awake as people in the general population. There’s been little research examining how medications affect driving performance.

The primary treatment options are wakefulness-promoting medications and stimulants taken during the day. Common medications include:

  • modafinil (wakefulness-promoting)
  • armodafinil (wakefulness-promoting)
  • solriamfetol (wakefulness-promoting)
  • pitolisant (wakefulness-promoting)
  • methylphenidate (stimulant)
  • amphetamine salts (stimulants)

You also have the option to take a medication at night: Sodium oxybate, which is a central nervous system depressant.

One small 2019 study examined participants with narcolepsy — or another sleep disorder called idiopathic hypersomnia — during real and simulated driving tests. Participants treated with 400 milligrams of modafinil had better results during their simulated driving performances than participants treated with a placebo.

Participants treated with modafinil still had poorer scores on a maintenance of wakefulness test than people without narcolepsy, but driving performance in the two groups was the same. A maintenance of wakefulness test is a type of multiple sleep latency test that measures how alert a person is in a stimulation-free place.

Caffeine may also be beneficial for improving driving performance in people with narcolepsy. A 2020 review of 45 studies found evidence that caffeine improves scores on tests of reaction time, attention, executive function, and vehicle control in the general population.

In a small 2020 study, researchers found that 200 milligrams of caffeine taken daily for a week reduced drowsiness and increased alertness in 16 people with narcolepsy. However, larger studies are needed to confirm these results.

People with well-controlled narcolepsy may be able to drive safely if they take precautions.

If you have narcolepsy and plan on driving, you can minimize your chances of having an accident by taking a 15- to 20-minute nap before driving. Research from 2020 suggests that naps of this length improve driving performance, but longer naps can cause grogginess.

Other ways to minimize your risk of motor vehicle accidents, according to this 2020 study, include:

  • avoiding driving when you’re particularly sleepy, like late at night or early morning
  • keeping trips short
  • taking nap breaks during long drives
  • taking turns driving with another person
  • avoiding driving after meals, or after consuming simple sugars or alcohol

If your narcolepsy is well under control, you may be able to drive safely by taking precautions. But it’s important to know your limitations. If your friends and family members are concerned, it can be a sign that you should give up driving in certain situations. You may consider cutting out driving entirely.

Your doctor can help you determine whether it’s safe for you to drive. They can assess your ability to stay awake during monotonous tasks.

This 2020 study suggested that people who are drowsy can’t reliably self-rate their impairment. Signs that it’s time to put the keys down for the day include:

  • an inability to focus
  • frequent yawning or trouble keeping your eyes open
  • nodding off or finding your head falling
  • missing road signs
  • not remembering the last few miles of driving
  • drooping eyelids
  • frequent daydreaming
  • trouble maintaining speed
  • drifting out of your lane

It can be difficult to know if it’s safe for you to drive. The study linked above notes that there are no standard guidelines for people with narcolepsy. However, if you answer yes to most of the following questions, it may be time to reassess whether you should be on the roads:

  • Do your friends and family think it’s unsafe for you to drive?
  • Have you fallen asleep at the wheel before?
  • Is your narcolepsy poorly controlled?
  • Have you gotten into, or almost gotten into, a collision that was related to drowsiness?
  • Have you experienced cataplexy or sleep paralysis while driving?

You can minimize your chances of an accident by:

  • avoiding sources of distraction (such as listening to music, talking with passengers, or using a cell phone)
  • avoiding driving after taking medications that can cause daytime sleepiness (such as antihistamines)
  • avoiding driving after eating or drinking alcohol
  • avoiding driving more than 30 to 60 minutes in a row
  • avoiding long drives and heavy traffic
  • taking naps before driving
  • pulling over if you find yourself getting sleepy while driving

Most people with treated narcolepsy are legally able to drive in the United States. But it might not always be safe for them to drive. People with narcolepsy are at a heightened risk of motor vehicle accidents. This is largely due to increased daytime drowsiness.

Your doctor can help you figure out whether it’s safe for you to drive by assessing your ability to stay awake. You can minimize your chances of getting into an accident by avoiding extended periods of driving and taking frequent naps.