Going 24 hours without sleep can lead to schizophrenia-like symptoms in healthy people, according to a new international study. The tired patients experienced several symptoms that would otherwise be attributed to psychosis or schizophrenia.
“It was clear to us that a sleepless night leads to impairment in the ability to concentrate,” said Prof. Dr. Ulrich Ettinger of the Department of Psychology at the University of Bonn. “But we were surprised at how pronounced and how wide the spectrum of schizophrenia-like symptoms was.”
For the study, scientists from the University of Bonn, King’s College London (England) and the Department of Psychiatry and Psychotherapy at the University of Bonn Hospital examined 24 healthy male and female participants aged 18 to 40 in a sleep laboratory.
At first, the volunteers got used to sleeping normally in the laboratory. A week later, they were kept awake all night with movies, conversation, games, and brief walks.
The next morning, participants were questioned about their thoughts and feelings and were also given a test called prepulse inhibition, designed to measure the filtering function of the brain.
During this test, participants hear a loud noise through their headphones. As a result, they experience a startle response, which is recorded with electrodes through the contraction of facial muscles. If a weaker stimulus goes off beforehand as a “prepulse,” the startle response is less dramatic.
“The prepulse inhibition demonstrates an important function of the brain: Filters separate what is important from what is not important and prevent sensory overload,” said lead author Dr. Nadine Petrovsky.
In the participants, this filtering function of the brain was drastically reduced following a sleepless night. “There were pronounced attention deficits, such as what typically occurs in the case of schizophrenia,” says Ettinger. “The unselected flood of information led to chaos in the brain.”
The tired participants also reported in questionnaires that they were somewhat more sensitive to light, color, or brightness. They also said that their sense of time and sense of smell were altered. Many even had the impression that they could read thoughts or notice altered body perception.
“We did not expect that the symptoms could be so pronounced after one night spent awake,” said Ettinger.
“In drug development, mental disorders like these have been simulated to date in experiments using certain active substances. However, these convey the symptoms of psychoses in only a very limited manner.”
Source: Journal of Neuroscience