Genetic Mutation Lets Some Thrive on Four to Five Hours of Sleep

Brad Johnson, a 70-year-old from Providence, Utah, sleeps only four to five hours a night and feels sharp and energized. He and several relatives carry a rare mutation in the ADRB1 gene, linking them to a group of only about 50 identified families worldwide with natural short sleep genetics. Johnson has participated in family sleep studies and says he cannot get more sleep even after a 24-hour travel day to Europe, where he may sleep six hours for a few nights but never seven or more. "I just can't get more than four or five hours of sleep. And I thrive on that," Johnson said. He lived with fear about his sleep pattern until researchers told him it was normal for a short sleeper, which changed his perspective.

What science knows about natural short sleep

Natural short sleepers have a lifelong biological need for less sleep. They typically wake on their own after four to six hours feeling restored and maintain the same routine even on vacation, without relying on alarms or caffeine. The pattern often runs in families. Ying-Hui Fu, a neurology professor at the University of California, San Francisco, has studied such families for decades. Her team, along with Louis Ptáček, helped establish a genetic basis for the trait by discovering a mutation in the DEC2 gene. Natural short sleep is linked to rare mutations in at least five genes.

Scientists study these individuals to understand how the brain determines sleep need and what sleep restores. Fu believes natural short sleepers may accomplish essential overnight work more efficiently. Sleep supports alertness, metabolism, glymphatic clearance, immune restoration, and mood.

Why most people shouldn’t try this

Habitual short sleep is different. It describes individuals who get by on less sleep using alarms and caffeine. According to a 2024 national health survey, nearly one in three U.S. Adults report getting less than seven hours of sleep daily. Chronic sleep loss is risky. A large meta-analysis links cutting sleep short over time to increased risks of obesity, diabetes, and coronary heart disease. Elizabeth B. Klerman, a professor of neurology at Harvard Medical School, warns that people are often poor judges of their own sleep needs. "People are very bad at understanding how much sleep they need," Klerman said. A 2005 study she co-authored found young adults slept longer when given more time in bed, suggesting their usual schedules created a sleep debt masked by caffeine or a forgotten sense of true alertness.

How sleep works-and what we still don’t know

Two biological systems govern sleep. Thomas E. Scammell, a professor of neurology at Harvard, explains these as the circadian clock, which times sleep, and homeostatic sleep pressure, which builds with wakefulness like hunger. The circadian waking drive acts as an internal morning alarm. Feeling alert upon waking does not necessarily mean the brain has finished recovering. It remains unknown whether natural short sleepers perform restorative processes faster, need less restoration, or differ in another way. One hypothesis from Chiara Cirelli, a sleep research chair at the University of Wisconsin, Madison, is that sleep allows synapses to reset. Some evidence suggests natural short sleepers preserve deep, slow-wave sleep despite sleeping less, possibly completing more synaptic work in less time. Scammell suggests determining individual sleep need by skipping the alarm for at least three nights and observing sleep duration on the third night. Scientists hope to understand how natural short sleepers complete essential brain restoration in less time and whether this could improve sleep treatments for everyone.