The way I see it: Stuttering happens when there's a mental disconnect between what you want and what you feel forced into. If you don't want to speak, perhaps out of fear, but feel forced to, then your whole vocal apparatus will be confused between whether it should shut up or speak up. Working on fear and any other 'blockages' is a smart way of resolving that disconnect. Another, unusual, way of resolving it is if you work on motivating yourself into wanting to speak and express ideas/thoughts. Can also work on it from the other end, reduce the pressure and obligation to speak up so it matches a little more to your desires and fears around speaking.