Imagine suddenly falling asleep mid-conversation. Or collapsing to the floor just because you laughed. For people with narcolepsy, this isn’t dramatic, it’s daily life.

Narcolepsy has been observed since the 18th century, but it was the French neuropsychiatrist Édouard Gélineau who first defined the condition. In 1880, he described patients with an uncontrollable urge to sleep. One of them, a 38-year-old wine merchant, also experienced sudden weakness in his legs whenever he laughed, felt pleasure, or even held a winning hand of cards. Gélineau would later document 14 cases, initially believing narcolepsy to be a new type of neurosis.

For years, the disorder puzzled physicians. In 1957, Yoss and Daly described the classic symptom tetrad: excessive daytime sleepiness, cataplexy (emotion-triggered muscle weakness), sleep paralysis, and hypnagogic hallucinations. Despite overwhelming sleepiness during the day, night-time sleep in narcolepsy is often fragmented and unrefreshing.

Real progress came after the discovery of REM sleep in the 1950s, allowing narcolepsy to be studied using polysomnography. More recently, researchers identified the loss of hypocretin (orexin) neurons in the hypothalamus as a key mechanism behind the disease—a breakthrough that transformed our understanding of its biology.

Narcolepsy usually begins in adolescence or early adulthood and affects about 1 in 2,000 people in the United Kingdom. Diagnosis is often delayed for years, and even with treatment, excessive sleepiness can seriously impair quality of life, increasing accident risk and affecting work, relationships, and mental health. Treatment focuses on stimulants to reduce daytime sleepiness and antidepressants to control cataplexy, sleep paralysis, and hallucinations, alongside psychological and social support.

Narcolepsy has also made its way into popular culture. One of the most striking portrayals appears in My Own Private Idaho (1991), directed by Gus Van Sant, where River Phoenix’s character, Mike Waters, lives with narcolepsy. His sudden sleep attacks—often triggered by emotional stress—are woven into the film’s visual language, blurring dreams, memories, and reality. While not a clinical portrayal, the film captures something deeply truthful about the condition: its unpredictability and the isolation it can impose, long before narcolepsy was widely understood by the public.

Here is a brief excerpt from an interview River Phoenix gave about playing a character with narcolepsy at the time the film was released.