It sounds like we have a few people in similar situations here.
As someone who is 30 years old and who went through a major bout of depression from my late teens-mid twenties, the best advise I can give, it to say FIGHT IT. Sometimes you have to force yourself to go out, even if it's just going for a walk for an hour.
Over several years - and it continues to this day - I have watched myself become increasingly withdrawn from my friends to the point where I only see them once every couple of months. I'm lucky that I also have good friends who I also work with 5 days a week, or else I would be almost completely isolated.
I'm not a drug user, and neither is anyone in my main old friendship group, it's just that our lives have taken us in different directions. Some make more effort to keep in touch than others, but I make the least effort of all. I wish I knew why it is. Just laziness and a lack of motivation, I suppose.
Teh moralz:
Fight it while you are still young, because once you reach a point where you feel it's too late to do anything about it, even if it's not true, it's a looooong way back.
