I'm not sure if this section is the right place to put this thread, let me know if it will be better off elsewhere.
My dp used to smoke weed a lot during his teenage years. When we met I was aware he still did every now and again. Recently its come to light that he has been smoking a lot more than I thought and as soon as he runs out he's buying more. I've noticed over the past few months a huge change in his moods, specially in the time when he's not smoking it (I can tell from his moods the day he's run out). He's nasty, selfish, short tempered, drowsy, anti-social and depressed when he's not had any and each time he does have a few days break between smoking these moods seem to get worse.
Its come to my attention that he's not been without weed for long since being 15 (he's late 20's now) and its made me realise I've got to know someone who's been fuelled by drugs and I probably don't know him at all. He knows how I feel and that I hate him treating me the way he does when he's without weed but we seem to go round in circles - He runs out of weed, He gets moody and wants to buy more, I tell him how I feel about that, he gets nastier, he calms down and opens up, makes promises that he will stop and get therapy and then the cycle starts again.
What I want to know is how addictive can weed really be? Will any particular therapy work? Is there such a thing as withdrawal symptoms from cannabis or is this nastiness his true colours?