A scientific study by psychiatrists Thomas Pollack and Philip Corlett has concluded that people who were born blind are immune from schizophrenia. The study was published by the US National Library of Medicine National Institutes of Health in 2019.
Pollack and Corlett wanted to determine whether previous reports of blind people being immune to schizophrenia were true. With no reports of people with schizophrenia and congenital blindness, scientists questioned if blindness caused immunity from schizophrenia.
“We present a number of relevant case-reports from different syndromes that show comorbidity of congenital and early blindness with schizophrenia,” said the report. “On the basis of these reports, we argue that a distinction between different types of blindness in terms of the origin of the visual deficit, cortical or peripheral, is crucial for understanding the observed patterns of comorbidity.”
Charles Bonnet first noted a condition in people who lost their vision and also began to hallucinate back in the 1760s. He called it Charles Bonnet syndrome.
The research also included monitoring how brain structures and genetics affected blindness and schizophrenia and blindness. The authors of the study wanted to understand how vision can help them better understand schizophrenia.
“It has been argued that vision science can significantly advance our understanding of schizophrenia (Silverstein and Keane, 2011b). The aim of this work was to explore aspects of the relation between absent vision and schizophrenia.”
Dr. Thomas A. Pollack, one of the study’s authors, is from the Institute of Psychiatry, Psychology and Neuroscience at King’s College London. Pollack believes there is a connection between blindness and psychotic disorders.
“The idea we’re trying to get at is, there must be something different in the representation and the stability of the internal world in congenitally blind people,” said Pollack. “And that stability, in a way, is keeping itself protective against the kind of mistakes and false inferences that you get in schizophrenia and psychotic disorders.”
Pollack’s colleague and associate professor of psychiatry and psychology at Yale, Dr. Philip Corlett, published their theory in Schizophrenia Bulletin in November of 2020.