For sure pot is addictive. Psychologically at least, anyway. Whenever I've relapsed, it was usually pot that started the decline. I'd always justify it by saying to myself, "Well pot isn't that bad. Nobody has any real problems because of smoking pot."
Boy, how wrong I was with that frame of thought. I should have over five years of sobriety, but instead I'm just coming back..........AGAIN.
If you have problems with alcohol and opiates, I would strongly advise staying away from pot as well. I'm not saying this because I read it in a book, I'm speaking from personal experience. My own, and MANY other addicts/alcoholics who've gone through the exact same situation.
Don't take the chance, because it isn't worth it.