Originally Posted by DarkJedi

you're comparing apples with oranges.
Depression doesn't have anything to do with your immune system. You're not sick. The problem is in your head, in your perception of things.

The drugs don't solve your problems. They don't "heal" your brain. They only make you feel good. The stimulate various areas and make shitty situation appear not that bad. Same with alchohol and hard drugs.

The more you get dependant on them, the less stress you can take in different life situations. And in time you can't live without them. But your problems stay the same.