While some signs may suggest if a person is at risk for developing schizophrenia, a definitive diagnosis is not determined until the psychotic fist episode occurs. But neuroscientists have now discovered an abnormal model of the brain that is linked to the development of schizophrenia.
Schizophrenia is a brain disease that produces hallucinations, delusions and cognitive impairments. The disorder usually becomes apparent during adolescence or young adulthood. The new research should feed studies that test the use of cognitive behavioral therapy and neuronal feedback as early interventions to combat the symptoms of schizophrenia.
In the new study, MIT neuroscientists working with researchers at the Beth Israel Deaconess Medical Center, Brigham and Women's Hospital and the Shanghai Mental Health Center have now identified a pattern of brain activity related to the development of schizophrenia.
The researchers believe that the discovery of the abnormal brain pattern can be used as a marker to diagnose schizophrenia earlier.
"You can consider this model as a risk factor: if we use these types of brain measurements, then perhaps we can better predict who will eventually develop psychosis, and this could also help to adapt interventions," said the dr. Guusje Collin, lead author of the article.
The study, which appears in the magazine Molecular psychiatry, was performed at the Shanghai Mental Health Center.
The researchers explain that before an individual occurs a psychotic episode – characterized by sudden changes in behavior and a loss of contact with reality – people can experience milder symptoms such as disordered thinking.
This type of thinking can lead to behaviors such as jumping from one topic to another randomly or giving answers that are not related to the original question. Previous studies have shown that about 25% of people experiencing these early symptoms develop schizophrenia.
The researchers followed 158 people between the ages of 13 and 34 who were identified as high-risk because they had experienced the first symptoms. The team also included 93 control subjects who did not have any risk factors.
At the beginning of the study, the researchers used functional magnetic resonance imaging (fMRI) to measure a type of brain activity that involves "resting state networks". Rest state networks consist of brain regions that connect and preferentially communicate one with the other when the brain is not performing particular cognitive tasks.
"We were interested in observing the intrinsic functional architecture of the brain to see if we could detect early aberrant brain connections or networks in individuals who are in the clinically high-risk stage of the disorder," says Whitfield-Gabrieli.
One year after the initial scans, 23 of the high-risk patients had a psychotic episode and were diagnosed with schizophrenia. In the scans of those patients, taken before their diagnosis, the researchers found a distinctive pattern of activity that was different from healthy control subjects and those at risk who had not developed psychosis.
The researchers found that in most people, a part of the brain known as the upper temporal gyrus, involved in auditory processing, is highly connected to the brain regions involved in sensory perception and motor control.
However, in patients who developed psychosis, the upper temporal gyrus became more connected to the limbic regions, which are involved in the processing of emotions. This could help explain why patients with schizophrenia usually suffer from auditory hallucinations, the researchers say.
Meanwhile, high-risk subjects who did not develop psychosis showed network connectivity almost identical to that of healthy subjects.
Researchers believe that this type of distinctive brain activity may be useful as an early indicator of schizophrenia, especially since it may also be seen in younger patients.
Source: MIT / EurekAlert