An excellent long read that looks at the rise of anti-depressants as treatments for chemical imbalances in the brain.

Link: https://qz.com/1162154/30-years-after-prozac-arrived-we-still-buy-the-lie-that-chemical-imbalances-cause-depression/

Spoiler, the short answer is they don't. But it doesn't stop us for looking for quick fixes and all the quacks in Western Medicine are far too happy to oblige.