Depression, like obesity, is acquired, habitual change due to environmental factors. Non fraudulent CBT (active traveling in a unfamilar environment as a simplest example) is enough to introduce persistent changes (that is why there are so many stories about profound changes people undergo after visiting the East - radical behavioral change will lead, through conditioning, to change in biochemistry - body is a dynamic, adaptive system).
There is, of course, no way to change one's physical or mental conditions without introducing changes to habits, daily routines and environment.
There is, of course, no way to change one's physical or mental conditions without introducing changes to habits, daily routines and environment.