As a counter point, I was on prozac (fluoxetine) for about a year after being diagnosed with major depression. Everything seemed better at first, but my personality changed in a way that, when I looked at it objectively, I did not like and eventually I felt as though the drug was merely masking depression that never actually went away.

My personal opinion having talked to doctors, therapists, and other depression sufferers is that the medical industry's treatment of depression is basically just throwing darts and hoping. They only kinda have a rough idea of how to treat some of the symptoms of depression and care not for any potential underlying causes. The "chemical imbalance" language, in my considered opinion, really does enforce this world view that depression is something you just throw drugs at until you're fixed, and I don't think that's helpful.