Narcolepsy: symptoms, causes and treatment

Key points

• Narcolepsy is a long-term neurological condition, not a mental health condition. The brain loses part of its control over sleep and wakefulness [1].
• About 30,000 people in the UK have it. Symptoms often start in the teens, diagnosis usually between 20 and 40 [1].
• The main symptoms are daytime sleepiness, cataplexy, sleep paralysis, hallucinations around sleep and broken night-time sleep [2].
• Cataplexy is a sudden loss of muscle control triggered by strong emotion, usually laughter, with the person fully conscious [7].
• Sleep clinics diagnose it after a GP referral [4]. Narcolepsy UK reports that some people wait more than 10 years [8].
• There is no cure, but naps, routine and medication reduce symptoms. Anyone diagnosed must tell the DVLA [1][5][9].

What narcolepsy is

Narcolepsy is a rare, long-term brain condition that can stop a person choosing when to sleep and when to stay awake [1]. It is neurological, not psychiatric. The brain cannot hold the line between sleep and wakefulness, so sleep pushes into the day and wakefulness breaks up the night [1][2].

If you need help now. Samaritans: call 116 123, free, 24/7. Shout: text SHOUT to 85258. NHS 111, then choose the mental health option. Call 999 if anyone is in immediate danger.

An estimated 30,000 people in the UK have narcolepsy, with symptoms usually beginning in adolescence [1].

The image of someone dropping off mid-sentence is a caricature. Narcolepsy is not constant sleeping: dreaming, and the loss of muscle tone that protects the body during dreams, intrude into the day, while night sleep is broken [2][7].

Symptoms

Narcolepsy has five main symptoms, and severity varies [2].

Excessive daytime sleepiness - An irresistible urge to sleep at inappropriate times, with sleep attacks that give little warning and microsleeps a person may not notice [2][6]. - Mental fuzziness, poor memory and low energy. A short nap often leaves the person refreshed for a while [6].

Cataplexy - A sudden, temporary loss of muscle control set off by strong emotion, most often laughter, but also excitement, anger or surprise [2][7]. - It ranges from a slight weakening of the face to slurred speech, buckling knees or a collapse [2][7]. - The person stays fully conscious, with hearing and awareness undisturbed, which separates cataplexy from fainting and from a seizure. Most attacks last under two minutes [7].

Around sleep and at night - Sleep paralysis, being briefly unable to move or speak, and vivid hallucinations while dropping off or waking. Both are harmless but frightening [2]. - Repeated waking, vivid dreams and nightmares, so night sleep is not restorative [2].

It is commonly confused with sleep apnoea, epilepsy, depression, an underactive thyroid and head injury, which can all cause heavy sleepiness [4].

Types

Narcolepsy has two types, with a smaller group of cases caused by damage to the brain.

• Type 1, with cataplexy. Linked to a shortage of the brain chemical hypocretin, also called orexin, which regulates wakefulness [3]. Around three quarters of people with narcolepsy have cataplexy, often starting months or years after the sleepiness [7].
• Type 2, without cataplexy. Sleepiness and disrupted sleep are present, cataplexy is not [3]. Hypocretin levels are closer to normal, and a shortage does not explain every case [3].
• Secondary narcolepsy. Caused by brain damage, for example after head injury, a tumour, multiple sclerosis or encephalitis [3].

Causes and risk factors

The most widely supported explanation is a shortage of hypocretin, thought to be autoimmune, with the immune system attacking the cells that produce it [3]. This does not fit every case: some people with narcolepsy have near normal hypocretin levels [3].

The NHS lists factors that may raise the risk or set off that response, while noting that research has not confirmed them all [3]:

• inherited genetic faults
• hormonal changes, such as puberty or the menopause
• major psychological stress, or a sudden change in sleep patterns
• infections, including swine flu and streptococcal infection
• the Pandemrix flu vaccine, at an estimated 1 in 52,000 doses, no longer used in the UK [3]

Stress appears there as a trigger, but narcolepsy is not a psychological reaction to a difficult period [3][6].

How it is diagnosed

Narcolepsy is diagnosed by a sleep specialist, not by a GP alone. The GP takes a history, asks about sleep habits and rules out other causes before referring on [4][8]. A sleep diary and a completed Epworth Sleepiness Scale, which rates how likely a person is to doze off in everyday situations, help at that appointment. A score of 11 or above usually prompts referral [4].

At the sleep centre, assessment may include:

• Polysomnography. An overnight study recording brain waves, eye movement, muscle tone, heart rate and breathing [4].
• Multiple sleep latency test. The next day, it measures how fast a person falls asleep in scheduled naps and reaches rapid eye movement (REM) sleep [4][8].
• Hypocretin measurement. A lumbar puncture samples spinal fluid, and a low level points strongly to narcolepsy. Narcolepsy UK reports the test is rarely carried out because the lumbar puncture is painful, while the NHS describes it as increasingly used by sleep specialists [4][8].

Delays are common. Symptoms typically begin in adolescence and diagnosis usually arrives between 20 and 40 [1]. Narcolepsy UK reports that some people wait more than 10 years [8]. Sleepiness, poor concentration and memory problems overlap with depression, one of the conditions ruled out along the way [2][4].

Treatment

There is no cure. Treatment aims to reduce the impact of symptoms [1]. Sleep habits come first, alongside any medication [5]:

• frequent, brief naps spaced evenly through the day
• a strict bedtime routine, with the same times each day
• avoiding caffeine, alcohol and smoking before bed

Medication is prescribed and monitored by a GP or specialist. Modafinil, pitolisant and solriamfetol help people stay awake during the day. Modafinil needs monitoring of heart rhythm and blood pressure, and should not be taken in pregnancy [5].

Sodium oxybate, a liquid taken at night, can improve loss of muscle control and night-time sleep, but it is not funded by the NHS in many areas [5]. Antidepressants, including SSRIs, SNRIs and tricyclics, are used for cataplexy, hallucinations and sleep paralysis rather than for low mood, and should not be stopped abruptly [5].

No one should start or stop these medicines without speaking to the prescriber. Treatment reduces symptoms rather than removing them [1][5].

Living with narcolepsy

Naps and a consistent bedtime are the foundation of daily management, alongside any medication [5]. The NHS advises telling teachers, employers and family, and notes there is no reason you should not be able to work where an employer makes allowances [5]. Explain cataplexy separately, because an attack looks like fainting: you stay conscious and can hear what is said, and it usually passes within two minutes [7].

Sleepiness in narcolepsy is not laziness. It is outside your control, though people often assume you could stay awake if you tried harder [6]. Narcolepsy UK offers information and support to families as well as patients [5].

Depression is recognised as part of the picture, and some people withdraw socially to avoid situations that might trigger attacks [1][2]. Years of exhaustion, of being disbelieved and of being treated for the wrong condition all contribute. If low mood persists, you can refer yourself to NHS Talking Therapies for anxiety and depression, or ask your GP.

When to speak to a professional

Make a GP appointment if:

• you fall asleep during the day despite sleeping enough at night, or sleepiness affects work, study or relationships [1][2]
• you have episodes of sudden muscle weakness set off by laughter, surprise or anger [2][7]
• you have been treated for depression or another condition but the sleepiness has not improved [4]

If narcolepsy is diagnosed you must not drive and must notify the DVLA. A licence may be issued only once symptoms have been controlled for at least three months, and bus, coach and lorry drivers face stricter conditions [10].

If you are struggling to keep yourself safe, call Samaritans on 116 123, text SHOUT to 85258, or call NHS 111 and choose the mental health option. Call 999 in immediate danger.

Common questions

Is narcolepsy a mental health condition?

No. It is a brain condition affecting the control of sleep and wakefulness [1]. It sits in mental health libraries because its daytime symptoms resemble depression, one of the conditions ruled out during assessment [2][4].

Is cataplexy the same as fainting or a seizure?

No. The muscles lose tone, but the person stays fully conscious, with hearing and awareness undisturbed [7]. It is set off by strong emotion, usually laughter, and most attacks last under two minutes [7].

How long does diagnosis take in the UK?

Symptoms often start in adolescence and most people are diagnosed between 20 and 40 [1]. Narcolepsy UK reports that some people wait more than 10 years [8]. Taking a sleep diary and an Epworth Sleepiness Scale score to the GP can shorten the route to referral [4].

Can a person with narcolepsy drive?

Not immediately. The DVLA must be told, and driving must stop until symptoms have been controlled for at least three months [9][10]. Not reporting it can bring a fine of up to £1,000 [9].

Clinical review pending

References

1. NHS. Narcolepsy. NHS. https://www.nhs.uk/conditions/narcolepsy/
2. NHS. Narcolepsy: Symptoms. NHS. https://www.nhs.uk/conditions/narcolepsy/symptoms/
3. NHS. Narcolepsy: Causes. NHS. https://www.nhs.uk/conditions/narcolepsy/causes/
4. NHS. Narcolepsy: Diagnosis. NHS. https://www.nhs.uk/conditions/narcolepsy/diagnosis/
5. NHS. Narcolepsy: Treatment. NHS. https://www.nhs.uk/conditions/narcolepsy/treatment/
6. Narcolepsy UK. Excessive daytime sleepiness. Narcolepsy UK. https://www.narcolepsy.org.uk/resources/excessive-daytime-sleepiness
7. Narcolepsy UK. Cataplexy. Narcolepsy UK. https://www.narcolepsy.org.uk/resources/cataplexy
8. Narcolepsy UK. Need to Know Guide: How is narcolepsy diagnosed? Narcolepsy UK, 2015. https://www.narcolepsy.org.uk/wp-content/uploads/2023/09/Narcolepsy-Need-to-Know-Guide-How-is-narcolepsy-diagnosed.pdf
9. GOV.UK. Narcolepsy and driving. Driver and Vehicle Licensing Agency. https://www.gov.uk/narcolepsy-and-driving
10. Driver and Vehicle Licensing Agency. Neurological disorders: assessing fitness to drive. GOV.UK. https://www.gov.uk/guidance/neurological-disorders-assessing-fitness-to-drive