In regards to the high levels of dopamine and serotonin I read a lot of articles online and studies indicating our dopamine levels are way higher than people that don’t stutter. That’s why sometimes psychiatrists will prescribe stutterers antipsychotics to level out the dopamine levels or lessen them. I also read that we are born with four mutated genes (if your stutter is genetic) that are damaged causing us to stutter. They did several studies on this compared to the average person and a person that stutters.