Depression is a subject close to my heart. I originally started off yoga with a whole "bouquet" of problems-- these included bronchitis, at the physical level, and at the emotional level deep and clinical depression, undiagnosed those days because I simply did not know it was a problem and thought it was personality trait that came from my background - poverty, familial problems as a child etc. . The reason I became awed by yoga and its corresponding sister sciences like Ayurveda (diet) and naturopathy was that it offered cure at a very sensible and commonsensical fashion. It also told me that I was not imagining what I felt, and that I could heal myself if I just continued in the path I was going, including eating the right food. It empowered me by allowing me to be my own healer. It is a puzzle to me why people struggle with yoga -- I mean, it gave me my life back.
Any case, this article in Rediff.com shares some part of the wonder. And it is written with the death of Robin Williams still fresh in my mind -- that a lot of depressives should not be given anti-depression pills because they are addictive, but just be guided firmly along the yoga and Ayurveda path for healing.
And if you did not know it (in a way I should be grateful my clinical depression was not diagnosed, because I would have been smothered with anti-depression medication) these pills, though originally they contain the problem, they actually make you suicidal. Nowadays I am told prescriptions for these are made for children who cannot cope with exam stress!! Horrible..