My husband tapered off methadone the past three months under doctor's care. He seemed fine as he finished the methadone two weeks ago. Well, this past weekend (a full week and a half after his final dose of methadone) he had violent fits of anger, unconsolable crying and was aggressive with strangers. He would scream at the top of his lungs and break things which isn't his normal for him. Does methadone stay in your system even after you've been off it for a couple weeks? Could this personality change be caused by methadone withdrawal?