Dream deprivation

Deprival of sleep from the "rapid-eye movement" phase restricts dreaming and causes the loss of concentration and cognitive abilities. Paranoia, hallucinations, and insanity are all common symptoms. While in a Tyken's Rift, the U.S.S. Enterprise NCC-1701-D crew's REM sleep was disrupted by the telepathic distress signals sent by an alien crew similarly stranded.