Can Sleep Deprivation Make You Hallucinate?

It's impossible to overestimate the importance of sleep when it comes to maintaining our physical and mental well-being. Sleep helps the brain function properly, and sleep deprivation has a negative effect on brain activity, according to the National Institutes of Health. It is common knowledge that going without sleep can make a person feel irritable, moody, and forgetful, but other side effects of sleep deprivation may be somewhat less expected.

We already know that sleep deprivation can exacerbate hallucinations among people with schizophrenia (via Sleep Medicine Clinics), but it turns out that it can have a similar effect on people who are otherwise healthy. Dr. Brandon Peters, a researcher at the Stanford Center for Sleep Sciences and Medicine, writes that around four in five healthy people will experience hallucinations if they go long enough without sleep (via Huffington Post). According to Frontiers in Psychiatry, these hallucinations can resemble schizophrenia, but there are a number of differences.

How and why sleep deprivation causes hallucinations

Researchers reviewed 21 articles and discovered that people generally experience blurred vision and visual distortions after going one or two full days without sleep (via Frontiers in Psychiatry). Eventually, a person will develop full-blown hallucinations. Initially, these symptoms tend to resemble those of eye disorders more closely than schizophrenia, since the hallucinations are mainly visual and are rarely scary, but symptoms tend to get worse with time. 

After five days without sleep, many people lose the ability to distinguish between reality and their hallucinations, leading to "acute psychotic symptoms." According to Frontiers in Psychiatry, these effects are probably due to changes in brain activity brought about by lack of sleep. 

Fortunately, the effects are not permanent, and can generally be resolved without any complications simply by getting enough sleep. So if you haven't slept in a while and you're starting to see things that aren't there, then all it probably means is that you need to get some sleep, and soon. If sleep disorders make this impossible for you, Healthline recommends working with your doctor to find a solution.