This is purely anecdotal, but it reminds me of the recent mental health revelation by Kevin Smith. He was baked all day, every day for 15 years, but quit cold turkey after checking himself into a facility for a month.

I thought his discussion about it was interesting. Clearly there was other stuff going on, but he apparently felt his cannabis use was enough of a contributing factor that he decided to stop. https://www.youtube.com/watch?v=JBvc7Ny4iUk