PALEO/PSYCHIATRY

It was a cold fact that smacked me in the face (or, rather, in my pre-fontal cortex) when I learned that schizophrenia affects 0.3% of persons in the entire world, AND that this statistic probably holds true for the entire history of homo sapiens, 300,000 years’ worth. Why, I wondered, would such a terrible disease persist and recure, presumably by advancing and maintaining its genetic basis generation after generation. What positive effect could be transmitted at that regular rate that would allow schizophrenia to persist among the entire human population down through its ages?