> That's not science, that's a cargo cult.
Science deals completely and exclusively with modeling "if this then that". And the breakdown for "if this then that" depends on the current observability of the scale you're trying to describe.
We don't know how gravity works, because we can't look inside gravity, we can only look at gravity's effects on other things, but we know that it does appear to work, and we believe that it works in the same way every time, and we can use observations and organized thinking to model gravity in a way that allows us to predict what will happen "if this".
So we can safely say we don't know how gravity itself works, but we can also safely say that we do know the relationship between gravity and mass, because that's something we can observe.
Likewise, we can safely say we don't know "how antipsychotics work inside the brain", but we can also safely say we do know "how antipsychotics work on populations", because populations are easily observed and inside the brain is not. Both use the word "how". The difference is what we're currently able to observe.
This is a language problem, not a science problem.
At an essential level, science can't answer how many things work, because the deeper into the unobserved you try to talk about (and the workings of the brain are still approximately 100% unobserved) "how", which is a question about things we can observe, becomes more and more a mis-use of the word "how" to talk about "why", which is a question about things we cannot observe, and science doesn't talk about things we cannot observe.
It would only be cargo culting if the "but...", which I assume went on to say "...it appears to be beneficial for many people", were instead "and we haven't bothered to observe whether it helps anyone". But again I assume that's not how the sentence ended.