Pattern of brain activity related to the development of schizophrenia

Schizophrenia, a brain disorder that produces hallucinations, delusions, and cognitive disorders, usually strikes in adolescence or early adulthood. Some signs may suggest that a person is at high risk of developing the disease, but there is no way to definitively diagnose it before the first psychotic episode.

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 correlated with the development of the brain. schizophrenia, which could be used as a marker to diagnose the disease. earlier.

"You can think of this phenomenon as a risk factor, so if we use these types of brain measurements, we may be able to better predict who will eventually develop psychosis, which may also help tailor interventions," said Guusje Collin. , visiting scholar at the McGovern Brain Research Institute at MIT and lead author of the article.

The study, which appears in the newspaper Molecular Psychiatry November 8, was held at the Shanghai Mental Health Center. Susan Whitfield-Gabrieli, a visiting researcher at the McGovern Institute and a professor of psychology at Northeastern University, is one of the study's lead researchers, alongside Jijun Wang of the Mental Health Center of Northeastern University. Shanghai, William Stone of Beth Israel Deaconess Medical Center. , the late Larry Seidman of Beth Israel Deaconess Medical Center and Martha Shenton of Brigham and Women's Hospital.

Abnormal connections

Before experiencing a psychotic episode, characterized by abrupt changes in behavior and loss of contact with reality, patients may experience less severe symptoms, such as thought disorders. This type of thinking can lead to behaviors such as jumping from one topic to another at random or giving answers unrelated to the original question. Previous studies have shown that about 25% of people with these early symptoms develop schizophrenia.

The research team conducted the study at the Shanghai Mental Health Center, as the large number of patients who come to the hospital each year gives them a fairly large sample of people at high risk of developing schizophrenia.

The researchers followed 158 people aged 13 to 34 who were identified as high risk due to early symptoms. The team also included 93 control subjects, who had no risk factors. At the beginning of the study, researchers used functional magnetic resonance imaging (fMRI) to measure a type of brain activity involving "state of rest networks". The resting state networks consist of brain regions that preferentially connect and communicate with each other when the brain does not perform any particular cognitive task.

"We were interested in examining the intrinsic functional architecture of the brain to see if we could detect early connectivity or aberrant brain networks in individuals in the high-risk phase of the disease," Whitfield said. 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 these patients, performed prior to diagnosis, the researchers found a distinct pattern of activity, different from that of healthy controls and at-risk individuals who did not develop psychosis.

For example, in most people, a part of the brain called the upper temporal gyrus, which is involved in auditory processing, is strongly connected to the brain regions involved in sensory perception and motor control. However, in patients who have developed psychosis, the superior temporal gyrus has become more connected to the limbic regions, which are involved in the treatment of emotions. This could help explain why patients with schizophrenia usually suffer from auditory hallucinations, say the researchers.

Meanwhile, high-risk individuals who did not develop psychosis had nearly identical network connectivity to healthy subjects.

Early intervention

This type of distinct brain activity might be helpful as an early indicator of schizophrenia, especially since it is possible to observe it in even younger patients. Researchers are currently conducting similar studies in younger populations at risk, including children with a family history of schizophrenia.

"This really shows how we can translate this clinically, because we can come in earlier and earlier to identify aberrant networks in the hope of being able to intervene sooner or even prevent psychiatric disorders," Whitfield said. Gabrieli.

She and her colleagues are now testing early interventions that could help fight the symptoms of schizophrenia, including cognitive-behavioral therapy and neuronal return. The neural feedback approach involves training patients to use mindfulness meditation to reduce activity in the upper temporal gyrus, which tends to increase before and during auditory hallucinations.

The researchers also plan to continue to follow patients in the current study and are currently badyzing some additional data on white-matter connections in these patients' brains to determine if these connections could result in additional differences that could also be of interest. early indicators. of the disease.