I don’t think depression is a universal root-cause diagnosis so I’m inclined to agree.

I’ve been diagnosed clinically several times in life with depression and the pills never did anything for me. Sometimes exercise worked, sometimes it was of little or no use.

With retrospect, all of my episodes of depression were a function of environment. As a child, growing up in a broken home situation and bad school environment, of course there is going to be depression. Life sucks. Further, no pill or weight lifting schedule is going to fix that either. Only breaking out of that situation will.

As an adult, I’ve absolutely had and broken out of a long episode of depression with exercise. Bad breakup, startup failure, then introduce chronic drinking and subsequent weight gain. Guess what, cutting back on drinking, bicycling to work 30 minutes each way, doing martial arts in the evenings, it was a great fix. It enhanced self image, added a new community of positive people, and broke a cycle of depression.