New Delhi: Over the decades, schizophrenia has been blamed on everything from the ‘schizophrenogenic mother’ to biology alone. Now a new US study has proposed something different: that social experiences such as childhood trauma, poverty, racism, and discrimination can become “biologically embedded” in the brain.
The study, published in the journal JAMA Psychiatry on 17 June, shows that exposure to adverse “social determinants of health” is associated with neurobiological abnormalities in schizophrenia, including in brain structure, function, and neurochemical levels. The study was carried out by researchers from the University of California-San Francisco and Carnegie Mellon University.
“What we wanted to know is how these environmental factors, such as stress, trauma and poverty, get under the skin, so to speak, and affect our biology,” Kaitlyn Dal Bon, a PhD student in cognitive neuroscience in Carnegie Mellon University’s Department of Psychology, said in a press release.
Scientists have long known that the conditions people grow up in, their professional and personal lives, have a significant impact on their health. Some studies even say that nearly 30 to 55 per cent of health outcomes depend on social conditions. However, the link between these social experiences and mental health is far less known.
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The study was the result of a systematic review of 114 studies analysing more than 10,000 participants with schizophrenia or at risk for developing psychosis. Most of the articles focused on the impact of early-life challenges including childhood trauma, along with a handful examining social disconnection, racism and discrimination, poverty, and food insecurity.
The findings revealed that social determinants of health often led to the reduction of the brain’s outer layer, also known as cortical thinning. Some regions of the brain even saw a reduced volume. Negative experiences were linked to lower structural connectivity between regions of the brain, altered patterns of brain activity, and abnormal levels of neurochemicals. All of these features are associated with schizophrenia.
However, researchers highlighted that no one factor is known to cause schizophrenia.
“One way to understand this link is to imagine that everyone has a cup, and everyone has different amounts of water in that cup, and perhaps some cups are smaller than others,” said Dal Bon. “Adding on these other factors, such as trauma or poverty, is like adding extra water to those cups. In the end, some people’s cups will overflow quicker than others.”
With their findings, the authors of the study want schizophrenia to stop being looked at as an incurable brain disorder. They highlight that by acknowledging the effects of social experiences, doctors could find individuals at high risk of developing schizophrenia and even develop targeted interventions.
“We need to understand how we can build resilience in these individuals, whether through focused therapy, some type of medication, family or social support, or some other kind of protective factor,” Jessica Hua, a clinical psychologist affiliated with the University of California, San Francisco, said in a press release.
(Edited by Asavari Singh)