These findings suggest that something about congenital blindness may protect a person from schizophrenia. This is especially surprising, since congenital blindness often results from infections, brain trauma, or genetic mutation—all factors that are independently associated with greater risk of psychotic disorders.
More strangely, vision loss at other periods of life is associated with higher risks of schizophrenia and psychotic symptoms. Even in healthy people, blocking vision for just a few days can bring about hallucinations. And the connections between vision abnormalities and schizophrenia have become more deeply established in recent years—visual abnormalities are being found before a person has any psychotic symptoms, sometimes predicting who will develop schizophrenia.
’A myriad of theories exist as to why—from the blind brain’s neuroplasticity to how vision plays an important role in building our model of the world (and what happens when that process goes wrong). Select researchers believe that the ties between vision and psychotic symptoms indicate there’s something new to learn here. Could it be that within this narrowly-defined phenomenon there are clues for what causes schizophrenia, how to predict who will develop it, and potentially how to treat it?…’
As a psychiatrist treating more than my fair share of patients with schizophrenia, I had never realized this but, no, I have never had a congenitally blind schizophrenic patient!