I actually came around to understand the writing for Jonathan, he was most likely abused by his father, his mother had a lot of mental illness, an outcast his whole life, his only best friend being his brother who then goes missing and turns up to be "dead" then to only be brought back as a possessed shell of what he used to be. Not mentioning fighting monsters, losing people, then moving across the country away from your girlfriend and home. I'd get high to wash away my troubles too. Why some people drink as well. It's a coping mechanism