Brain Wave Activity Seems Slower in Schizophrenics

But some suggest the finding may be due to medication

Randy Dotinga

Randy Dotinga

Updated on November 11, 2004

THURSDAY, Nov. 11, 2004 (HealthDayNews) -- New research suggests that schizophrenics process information at a lower frequency than healthy people, almost as if their minds were filled with bad connections.

"It is like a glitch," said Dr. Robert McCarley, deputy chief of staff for mental health services at VA Boston Healthcare System. An "out-of-sync" brain leads to symptoms such as hallucinations and disorganized thinking, some of the characteristics of schizophrenia, he explained.

The findings could lead to better understanding of the mysteries of schizophrenia, a complex brain disorder that affects an estimated one in every 100 Americans.

However, one neurologist suggested the apparent dysfunctional brain activity detected in the study may simply be a product of medication, not the disease itself.

The study appears in this week's issue of the Proceedings of the National Academy of Sciences.

An estimated 2.2 million people in the United States struggle with schizophrenic. They lose touch with reality -- they see and hear things that aren't real, have trouble focusing and may become paranoid. In some cases, schizophrenics become unresponsive.

Using electroencephalogram (EEG) technology, McCarley and his colleagues scanned the brains of 20 healthy people and 20 schizophrenic patients. They studied the 40 people's responses when they looked at an optical illusion that forced them to create an imaginary square shape in their mind.

The researchers found that the neurons of the schizophrenic patients communicated less quickly than those of the healthy subjects. It took the schizophrenics about 200 milliseconds longer to process the optical illusions.

McCarley and colleagues also found that neurons in those with schizophrenia communicated at a lower frequency than in the healthy people. Neurons send different types of information to each other and help the brain piece together a variety of facts into one coherent whole.

"For example, if you see a fire truck, you hear the bell, you smell the motor, you see the red, you see the movement," McCarley said. "All of these sensations are registered in different parts of the brain. You put them together to get your picture of a fire truck."

The neurons of the brain communicate most effectively at a frequency of 40 cycles per second, McCarley said. But in the schizophrenic patients, they communicated at lower frequencies; they were lowest in the patients with the worst symptoms.

The difference in frequencies doesn't mean it takes longer for information to travel between neurons, McCarley said. Instead, it means the information transmission isn't very efficient. "It's as if your brain is not putting things together quite right," he said.

The next step is to figure out ways to use drugs to improve the brain's inner communication system in schizophrenic patients, McCarley said. "You look for possible reasons why these cells aren't communicating at the best frequency," he added. "It may be that we need a new generation of drugs."

However, not everyone agrees with McCarley's interpretation of the importance of brain waves in individuals with schizophrenia.

Dr. James Grisolia, a neurologist at Scripps Mercy Hospital in San Diego, said the brain waves of schizophrenics slow down because of the medications they take. Indeed, the schizophrenic patients in the study were all on medication. But McCarley said the frequencies of the brain waves remained low, regardless of how much medication the patients were taking.

Grisolia added that the focus on brain waves misses the point. "The schizophrenic brain is different from the normal brain in ways that we still don't understand, but brain wave patterns will always be a sign of the problem, rather than the cause," he said.

More information

To learn more about schizophrenia, visit the National Institute of Mental Health.

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