"Studies discussed provide evidence of a dysfunctional hyperdopaminergic state of the thalamocortical pathways underlying speech motor control in stuttering." - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4233907/ (not sure how much neurosci you or whoever is reading has studied, so to simplify: studies have found too much dopamine in one of the main pathways in the brain of pws when it comes to motor control of speech. The thalamus is a relay center, so it sends/receives/modulates many kinds of sensations and movement.) Dopamine receptors are lightly sensitive to serotonin, so having more serotonin than usual (due to Prozac for example) could make it so that your dopamine receptors take the extra serotonin and release it again when their neuron fires. ( https://www.ncbi.nlm.nih.gov/pmc/articles/PMC558164/ ) Where did you see that prozac adds Dopamine?