First and foremost my personal experience but generally speaking these drugs have tons of side effects, are difficult to quit & yes they can lead to violence towards oneself & others (a # of school shooters, perhaps even most of them, including Eric Harris of Columbine infamy was on SSRIs). And, while I could never imagine what it must be like to be so far gone as to take such actions, I did feel a degree of coldness/repitilianess I might even say, while on Prozac in particular. Usually in school if kids messed w me I'd ignore it & go about my business. While on Prozac I did not tolerate it and allowed myself to be goaded into a fight that ended up w me ultimately dropping out of school (I was suspended for a fight in which I didn't even throw a punch, leading me to miss a track meet which was pretty much my only pleasure in school at that time & I was so fed up I simply quit school), I had less fear of consequence, I remember riding my bicycle crazy in the streets & then falling, skidding up the whole side of my torso & having an odd lack of concern over it. It's like my natural empathy/sensitivity, which made me susceptible to depression in the first place (along w
ritalin from age 7 til 12) got turned down which indeed did "help" me become less depressed but at the price of part of my soul (I'm atheist but not sure how else to phrase it)
It's just a crap-shoot, even today there is very little understanding of how these drugs work & no way to predict how a particular person's brain will react to them. One of my psychiatrists admitted as much. I was put on Effexor as a kid and my blood pressure shot thru the roof & I had severe anxiety, an ex of mine as an adult was on Effexor and it had dramaticly different effects on her (and it was hell for her withdrawing from it even though she was on a very low dose, you can read threads 1000s of posts long about people's experiences withdrawing from this drug, technically an SNRI but with similar problems & side-effects).
For myself, yes. I was failed by it as was my best friend in college who was suffering severe depression & alcohol addiction & was "treated" by his psychiatrist by being doped up on a cocktail of anti-anxiety & anti-psychotic pills (he was not psychotic but prescribing anti-psychotics to manage anxiety & even for sleep is common practice, or at least was in the 90's/early 00's). These drugs didn't help him but did numb him out/sap his energy to the point where he gained about 80lb (alot of weight on a 5'6" frame). He eventually committed suicide (via alcohol poisoning combined w his psych meds), he was only 24 or 25.
I wish I could've been a better friend & of more support to him & for years afterward I'd have dreams he was still alive after all & I had one last chance to reach him.
In general, the psychiatric industry is corrupt, individual doctors may care & do their best to help, but the system they are part of is driven by $ not helping people. Anti-depressants certainly help some people. They didn't help me & it took me over a decade to get off all those drugs completely.
Telling someone they have a "chemical imbalance" and selling them drugs is... well, not science. "Self-medication" is a derogatory expression in psychiatry but I've found it much more helpful than entrusting my precious brain to the pharmaceutical industry who's motivation is profit. I'm not glorifying this, it sucks, having to try to heal myself by trial & error, reading all manner of psychology/self-development books (some great, many garbage) but I don't miss the stress all through childhood of wondering whether what I was feeling was really "my" feelings or some chemical generated anxiety/mania/insomnia/etc (on top of everything else I was going through at that time).
Mental illness and depression in particular has been rising steadily in the last half dozen decades or so, right along with the rise in anti-depressant use. The problem has gotten so severe that the average life-span of a US citizen has actually gone down over the last few years IIRC, and it's not due to lack of enough prescribed pills, quite the opposite.