I had a college friend who claimed it wasn't addictive, and then became addicted. Towards the end of freshman year he quit school for a couple weeks, just to determine he couldn't stop smoking and went right back. Last I spoke to him he was still trying to quit, and he had a new method of locking the weed in a box to limit his use.
His withdrawals included him becoming extremely anxious, which is presumably why so many people think the weed helps with their anxiety. In 30 years we're going to look at weed like a slightly different version of cigarettes and wonder why anyone legalized it knowing what the consequences would be.
Weed isn't physically addictive. Forming habits is a very different thing though - anything can become addictive if you train yourself to need it. I've known heavy smokers who couldn't eat or function normally without weed, but people with less structured and intense habituation who use similar amounts over similar lengths of time without any issues.
His withdrawals included him becoming extremely anxious, which is presumably why so many people think the weed helps with their anxiety. In 30 years we're going to look at weed like a slightly different version of cigarettes and wonder why anyone legalized it knowing what the consequences would be.