It depends, a therapist wouldn't tell you how to talk or what techniques to use. But if you have anxiety, stress, or depression due to stuttering he would help you to deal with those feelings and be able to manage them. For example I had serious anxiety before making a phone call or talk to a stranger and with psychotherapy I manage to control it. So in my case stuttering wasn't the real problem, that's why speech therapy hadn't any permanent effect. It was the "negative" feelings that made a loop in my mind and I couldn't manage it. So, yeah try it and see what works best for you.