A 2001 study at the Chicago Medical Institute suggested that sleep deprivation may be linked to serious diseases, such as heart disease and mental illness including psychosis and bipolar disorder. The link between sleep deprivation and psychosis was further documented in 2007 through a study at Harvard Medical School and the University of California at Berkeley. The study revealed, using MRI scans, that sleep deprivation causes the brain to become incapable of putting an emotional event into the proper perspective and incapable of making a controlled, suitable response to the event.

What's the best answer to this question: can you get psychosis from lack of sleep?
yes