Well I've suffered in the past from depression, panic attacks, anxiety and all the rest of it, but I never opted for the pill-popping option. Seems a bit unnecessary when a degree of patience and self-discipline will suffice. I mean sure, you may not know how things will turn out when you first summon the resolve to persevere, but knowing that states of mind are all necessarily transient helps. Because sure enough it's not just a matter of persistent endurance in the face of one's pain, it's also the understanding of one's psyche and the identification of the adverse thought patterns that cause or worsen one's depression. If one knows what those patterns of thought are one can abstain from them, or distract one's attention away from them, and if you understand that states of mind pass, without your forcing them to, you can give yourself the motivation to be patient.
As has been said, proper diet and lifestyle are factors, but of course they're not the only ones. I don't believe any thinking person could seriously entertain the notion that something as complicated as depression could have a single cause. And if someone has deep-seated psychological or emotional issues then its highly doubtful that regularly running 10k or eating healthily is going to cure them.
I fucking love pharma companies. They save my life over and over.
This suggests to me that rather than saving your life by dealing with the source of your problem they've just made you chemically dependent on their product.