Thinking about so many people who have suffered lifelong depression: Hemingway, Lincoln, Churchill, make your own list, and then look around at your own family and friends, if not closer to home. Not conclusive, of course, but suggestive.
http://www.schwartzreport.net/depression-actually-nothing-allergic-reaction/?utm_source=Stephan+Schwartz%27s+Email+List&utm_campaign=a0633c87ac-SR_Daily_Digest_2016&utm_medium=email&utm_term=0_0eb25d4404-a0633c87ac-221392153