There was only the briefest mention of anxiety and depression in this story. Also, sounds like this boy moved into a new high school when he was in his teens. I am no expert, but I know some about mental illness, family upheaval, and addiction through emotional turmoil. I have some limited experience  working with troubled kids in outdoor/wilderness settings. Check out Outward Bound for one example of options for kids before they become addicted. Many depressed kids become mentally isolated and "ingrown", and are only able to look outside themselves when taken away from comfortable surroundings. It is very often effective at lessening depression and anxiety, and lets them see they must accept responsibility for themselves. Certainly worth a try when it seems they're headed for drug addiction. I'm very sorry for your terrible loss, family.