There's a legitimate case for psychoactive meds being overprescribed, sometimes to tragic results, but most other drugs are at least trying to treat real problems based on real empirical evidence. Yes, there's marketing of the hot new thing that's supposed to be magically better, and yes the companies are greedy fucks who gouge the public, but that doesn't make the drugs inherently unnecessary.
The problem with psychoactives is there's (usually) no blood test, no rash, no scan, not even a clearly articulable "I have a pain right here", and our understanding of brain chemistry remains so limited that even if you can fully satisfy yourself that "yes this person is clinically depressed", or "yes this person is schizophrenic", the actual results of the medication varies so widely that it often ends up being a long process of trial and error, occasionally punctuated with psychotic breaks and/or suicide attempts, and the entire time there's the niggling detail that sometimes these things eventually just "go away" and the meds might stop being necessary at all.
This is exceedingly different from most non-brain-related medical cases, where standard dosages of standard drugs usually do whatever they're supposed to with few (and minor) side effects and that's the end of it. You can test for infections, blood pressure, organ function, blood sugar, etc. and most patients are perfectly capable of telling you their leg hurts like hell and would you please X-ray it and inject some morphine before they bite your head off.
Psychiatric and neurological problems are a lot like heisenbugs -- you might know they're there, but you're not sure _what_ they they are, _where_ they are, or how to fix them. And when you go looking, you might set off some latent bug that blows up the whole damned system.