Schizophrenia is the price we pay for minds poised near the edge of a cliff

> For instance, if schizophrenia risk genes were not under positive selection, we would expect them to be purged from the gene pool over thousands of years.... Let’s say schizophrenia is associated with a 50% loss of reproductive fitness in 1% of the population (and there is no offsetting benefit in the rest of the population), then it would take roughly 180 generations to cut the rate in half and about 560 generations to reduce it to one-tenth of its original value (Mitteroecker & Merola, 2024). We’ve had a comparable number of generations since the Neolithic era, but as far as we know, the prevalence of schizophrenia has not decreased in the manner anticipated.

... Okay, but you already acknowledged that

> The process will be slow, but it will happen (this is not the same as saying schizophrenia itself can be eliminated, since it is highly polygenic and the pool of risk genes is not static).

So how do we know that modern-day schizophrenia isn't caused by a different set of genes? Maybe the Neolithic ones have been dying out from the gene pool, but new ones have consistently managed to keep replacing them. New genes can start contributing to the incidence of schizophrenia right away; even if they're otherwise neutral, they but won't die out due to the marginal effect on schizophrenia incidence for a very long time (much longer than the calculation above - since each one is, as we already established, causing only part of the loss in reproductive fitness). They don't need to be under positive selection, unless I've misunderstood something.