He'll have times of sobriety but anything stressful (happy or sad) happends can trigger him to use again. It's right now his only coping mechanism so it's his fall back. Once he relapse it starts from where it left off. It doesn't gradually grow it's a full blown addiction. I'm not saying he will always relapse but he needs to build good coping skills. That may mean NA meetings every night a therapist and pdoc. I'm a firm believer that addiction only happens in mental illness.