The funny thing about snake oil is that it actually does have health benefits. The Chinese brought snake oil made from a Chinese water snake with them to America when they came to build the railroads. So it's not the snake oil that is the problem. It's the snake oil salesmen who either diluted it or used another oil that had no medicinal effect and told people it was the real deal.
Long story short, I agree with you that the doctors prescribing the psychotrophic drugs are snake oil salesmen. People get depressed when their lives are far too easy and find that an easy lifestyle, which you are told will make your life enjoyable, is totally unfulfilling. Those who promote the easy life as the path to happiness are also snake oil salesmen.