Cause identified in Schizophrenic Hallucinations

June'1997

Scientists reported this week in the journal Nature, that they have identified brain circuits that appear to make schizophrenics hear voices and see things that aren't there.

This finding may help scientists develop better treatments for hallucinations. In the study it was reported that the researchers studied six schizophrenic patients: five who heard voices and one who heard voices and saw things. The patients lay in a PET brain-scanning machine and were told to push a button when they heard voices.

Using new techniques to scan the brains and analyze the results, researchers found that during the hallucinations, interconnected areas deep within the brain's core and other areas on the surface were activated. The core regions normally serve as meeting grounds for thoughts, emotions and perceptions, so that a person's current and past experiences can be compared with each other and associated with emotional reactions. The surface areas on the sides and the back of the brain normally process information from hearing and vision.

When the network of core and surface areas is turned on, "the brain is creating its own reality and believing it,'' said Dr. David Silbersweig, a neurologist and psychiatrist at the New York Hospital-Cornell Medical Center. The particular areas activated on the brain surface may determine what patients hear or see in hallucinations, researchers said.

When healthy people hear real voices, their brains show similar patterns of activation on the brain surface, but fewer of the core regions turn on, Silbersweig said. The work gives clues about where to look for the basic defect that turns on the hallucination circuitry, Silbersweig said. That could help scientists find new ways to suppress hallucinations. Silbersweig, colleague Dr. Emily Stern and scientists from England reported the results in Thursday's issue of the journal Nature. The work was done in England.

Dr. Michael Flaum, co-director of the Mental Health Clinical Research Center at the University of Iowa in Iowa City, said he found the work "a very credible study'' that proposes an attractive hypothesis for how the brain produces schizophrenic hallucinations. Hearing voices is the most common kind of hallucination in schizophrenia. Derogatory or threatening messages are especially common. Five of the patients heard voices almost constantly despite taking medication. "If they would just relax and be quiet, the voices would come to them,'' Silbersweig said.

In one report on this new discover it stated that "The voices talked to the patients and about them, generally saying derogatory things like "You are bad.'' The patient who also saw things was a 23-year-old unmedicated man who saw rolling, disembodied heads that gave him orders." These imaginary voices are common descriptions of the types of hallucinations that people with schizophrenia experience. For a free tape that has been created to give people a better understanding of what it is like to have schizophrenia, the Pharmaceutical company "Janssen pharmarceuticals" has created a tape that you can order. Click here for details on how to order this tape.