Can sleep deprivation cause hallucinations?
Yes. In studies of healthy volunteers, perceptual distortions start within 24 to 48 hours without sleep, complex hallucinations appear after 48 to 90 hours, and by the third day hallucinations can involve sight, touch and hearing.
The timeline
A 2018 systematic review of 21 studies (760 people) found: within 24 to 48 hours, perceptual distortions, anxiety, irritability and time disorientation; after 48 to 90 hours, complex hallucinations and disordered thinking; after 72 hours, delusions, with a picture resembling acute psychosis (Waters et al., 2018).
The mechanism
The exact mechanism is not settled. One idea is that sleep loss disturbs how the brain filters and interprets sensory input, so ordinary signals are misread.
Recovery
A period of normal sleep resolved the symptoms in many, though not all, cases (Waters et al., 2018). If you see or hear things that are not there without extreme sleep loss, see a doctor.
Sources
- Waters et al., Frontiers in Psychiatry, 2018. Severe sleep deprivation causes hallucinations and a gradual progression toward psychosis with increasing time awake
- Matthew Walker, Why We Sleep (Scribner, 2017). Why We Sleep: Unlocking the Power of Sleep and Dreams
Tired of hitting snooze?
ByeBed replaces the snooze button with a mission: math, push-ups, a photo. Stop the alarm without finishing the mission and it comes back, up to 10 times over 15 minutes. Subscription required, with a 3-day free trial on the annual plan for eligible new subscribers.
Download ByeBed on the App Store