I've been on anti-depressants since I was 17. I'm 30 now. Buproprion works best for me, to which I later added lamictal.
Prior to that, I'd been depressed since I could remember. In hindsight, I may have had mild aspergers like symptoms, mostly related to reading social cues. This wasn't "just growing up" despite shrinks for years telling me it was.
Finding the right anti-depressant changed my life for the better. Absolutely changed my life. After college, I went off them for a year just to see if I "needed them" any more. Within 6 months, I noticed my thoughts slip into old patterns of hopelessness, counterproductivity, loneliness, and general loops of existential pain, and this outlook effected everything and everyone around me. I do need them, it turns out.
So I wish people around me hadn't been so against drugs. In my case, they should have tried them earlier in treatment. That would have saved me some years of suffering.
Also, I tried prosac, lexapro, and effexor before buproprion. If I'd listened to the many drug critics, I'd have stopped looking after prosac (side effects there included sexual disfunction and mania). I notice no notable side effects with my current cocktail.
Also, I've exercised and been in good shape both pre and post taking anti-depressants. I feel better if I'm exercising than not, but it's not even in the same ballpark as what the drugs do for me. Everyone should exercise, not everyone benefits from anti-depressants. No exaggeration, I'd be dead without them.