Yep. Except Marijuana, as a substance, is not addictive. If a person has an addictive personality, anything can become addictive, including marijuana, but the substance itself is not addictive. Not like cigarettes. Not like alcohol.

Also, if you take enough of the drugs you mentioned, you'll die. You can smoke as much marijuana as you want, and the worst that will happen to you is you'll fall asleep.