Is my brother in psychosis?

My brother (29M) smokes weed every day. He can’t keep a job. He’s always saying there are people out to get him and he’s always threatening to beat up family and friends. He’s stuck in the past and has these memories of childhood that he keeps bringing up where everyone has done him wrong. I’m scared he’s going down that path if he’s not there already. The weed is a big concern of mine since I read a lot of people get weed induced psychosis.