
A new study shows why caffeine hits young brains harder during sleep.
Even when you manage to fall asleep after drinking caffeine, your brain doesn’t truly rest. It stays locked in an active and alert state throughout the night, according to new research.
“Caffeine is the most widely consumed psychoactive stimulant worldwide. Yet important gaps persist in understanding its effects on the brain, especially during sleep,” the study authors wrote.
When Your Brain Can’t Rest
The study, recently published in Communications Biology, found that caffeine increases what scientists call “criticality” in the brain—essentially keeping neural activity too active and chaotic during sleep when it should be winding down for recovery.











