I don't know enough to really have a worthwhile opinion, but for the sake of arguing (tldr: here, have some talking points I've seen on the internet):
Not every cure comes in pill form. Other than maybe a painkiller, you wouldn't really take anything to recover from severe injury, for example--you would do physical therapy. Grief counseling is an example.
Part of the problem with mental illnesses is that we know very little about them (particularly personality disorders--at what point do we call someone abnormal?) We can say "chemical imbalance in the brain" all we want, but for such a simple-sounding diagnosis, we lack any sort of cure-all because every case is a little different (quite like cancer now that I think about it, or the thing with flu vaccines). And unless you're dead, it's a little difficult to actually test brain chemistry and figure out exactly what's wrong. Because of all of this, any given medication works for some people but is ineffective in others.
I'd also bring up the "America takes a crapton of pills already" argument, though it strikes me as a little... I dunno. Simplistic? Who says those pills aren't effective?
Lastly, studies do show that a positive attitude helps out with a wide variety of diseases.
Again, just posting for the sake of argument. Don't know very much on the subject.
----------------------------------------
As for me, I react to stress with sadness. I think. It's bizarre. As soon as I have something due I get super apathetic about actually doing it (so many last-minute essays and compositions LOL -- yeah, I'm a music tech/composition major), but like now when I'm on break I'm chomping at the bit to continue. Gonna correct a couple mistakes I made this semester, ready to roll for January.