Schizophrenia Is Costly, So Why Didn’t Evolution Remove It?

Schizophrenia affects around 23 million people globally, or one in 345 people. The illness can beset sufferers with significant impairment in their personal, social, educational, and occupational endeavors. It can be characterized by debilitating symptoms such as delusions and hallucinations, restricted speech, and emotional expression.

Given the depth of these symptoms on psychological processes, such as forming and maintaining relationships, a simple evolutionary view would likely have predicted that schizophrenia “should” have been de-selected from the human gene pool. Studies have suggested the (genetic) fitness loss that results from schizophrenia can range from 20 to 70 percent. The ongoing stable global prevalence of schizophrenia is an example of an evolutionary paradox.

One theory, applied to schizophrenia by

visit website