I've stuttered since birth, but there was a period of time in my life between the ages of 15 - 18ish where I didn't stutter. It came back once I started my first real job. I thought I lost the stutter, but I realize that during that time of my life, I had very little stress. I wasn't experiencing any real anxiety, and I think that's why I wasn't stuttering. I really do think a stutter is affected so much by our psychological state. The older I get, the worse my social anxiety gets, and the worse my stutter has gotten. I know was born with a stutter, not an exact result of psychological troubles, but my state of mind directly affects my speech.