- According to Inserm, one in five people has suffered from depression in their lifetime or will suffer from it.
- Schizophrenia affects about 0.7 to 1% of the population worldwide and 600,000 people in France.
In 2019, one in eight people worldwide – or 970 million people – suffered from a mental disorder the world health organization (WHO). These can be defined as clinically severe impairments in a person’s cognitive status, emotion regulation, or behavior. There are a few.
Gray matter decreases in certain areas of the brain
The researchers wanted to understand the regions of the brain involved in several of these mental disorders. They isolated six: depression, anxiety, schizophrenia, bipolar disorder, substance abuse and obsessive-compulsive disorder (OCD).
To study them, they analyzed the brain data of 15,000 people. Some of them did not suffer from mental illnesses, while others did. Your results will be published in the journal nature of human behavior.
In those suffering from mental disorders, certain areas of the brain were affected. These are the anterior cingulum, an area associated with emotions, and the insula, an area associated with self-awareness. Inside, the gray matter has been reduced. However, these brain regions are also affected Neurodegenerative Diseases.
Mental illness: Violations in the transdiagnostic network increase the risk
To better understand how mental disorders affect the brain specifically, they analyzed the connectome, an existing map of human brain connections. Thus they discovered a network specific to gray matter decreases that is common to all diagnoses of mental illness, it is the transdiagnostic network. For mental illnesses, it would not be the result of the decrease in gray matter that would be important, but the course of this change.
To narrow their research, the scientists analyzed the medical records of 194 Vietnam War veterans. You had a brain injury. The goal here was to see if the affected area had an impact on the mental disorder diagnosed in these veterans. And the results are compelling: indeed, those who had violations in the transdiagnostic network were more likely to have multiple psychiatric disorders.
Psychiatric and brain disorders: ‘more in common than thought’
Nevertheless, according to the researchers, the reduction in gray matter in the anterior cingulum and insula is not – contrary to what was previously assumed – the cause of the mental illness, but rather a consequence. “We found that damage to these regions—the anterior cingulate and insula—correlated with less psychiatric illness, so atrophy of this cingulate and insula may be a consequence or compensation for psychiatric illness rather than a “cause” of it.explains Joseph J. Taylor, one of the authors, in a communicates.
Scientists hope that identifying this transdiagnostic network specific to psychiatric disorders will enable new studies and new advances in understanding and managing mental disorders.
“Psychiatric disorders are disorders of the brain, and now we’re just beginning to have the tools to probe and modulate their underlying circuitry.concludes Joseph J Taylor. There may be more similarities between these diseases than we originally thought.”