Well i can kind of relate to the cocaine thing. I don't do do blow. But i take Concerta (amphetamines) for ADD and it effects my stutter. If i take it for the first time after not taking it for a week i don't stutter at all because i can feel the stimulant effecting me and i focus on that. But after i take a whole precipitation (30 days) after about a week of daily use it makes my stutter worse. If i don't take it for one day, i don't stutter because i feel physically different for that day. In my limited experience with Benzos i did not stutter at all. I took a xanax once before i had a surgery coming up i was nervous about. And i was amazed i didn't stutter at all. But the problem was i became apathetic to everything and i didn't like that. I posted in another thread yesterday about how I recently got a second hand high from someone smoking pot in the car with me. It effected me just enough to get me loose but not high to the point i was inebriated. I didn't stutter at all. I took the opportunity and talked as much as possible while the effects lasted i loved the ability to let loose and talk freely. I truly believe my stutter comes from some subconscious fear or stress that i cannot pin point. So i am looking into different kinds of introspective mind altering substances to help me look inwards where i cannot do on my own.