Also, in many cases medication can really help people. Sometimes the reason doesn't matter so much as the end result. A good example of this is medication for schizophrenia. It was discovered by accident, but it can be incredibly effective, so why not give it to people, even if we don't know how or why it works? It works, which is the most important part.
My post was a side comment on a related topic, specifically tied to depression. I don't know enough about schizophrenia (for example) to refute the general case. It is not true for depression. You shouldn't reach straight for the meds before you know what you're dealing with, or have at least ruled everything known as reasonably unlikely.
Depression can strike people who don't really have any reasons for it. It can absolutely be just caused by a random shift in the levels of some brain chemicals.
There is a reason for it, even if we don't know what it is. The cause can vary wildly from case to case, but there is one. And I'm not arguing against SSRIs, SNRIs, TCAs, and MAOIs in each and every case. There are many, many patients that we (society) cannot otherwise help. They should simply NOT be the first thing the doctor thinks of.
There are so many "depression" patients with undiagnosed, treatable illness that it is simply not funny. They're living with less depression than they would if they weren't pilled up, but it won't go away until they're actually treated for what is actually wrong with them.