I know that stuttering is a neurological condition caused by dysregulated neurotransmitters in the basal ganglia, Brocas Area and Striatum. PET and fMRI scans indicate the stuttering brain has dopamine over-activity in those areas compared to non-stutterers. Baclofen simply acts similar to alcohol by flooding areas of the brain with GABA (without the other negative affects of alcohol like slurred speech and loss of motor control etc). That’s why stutterers report improved fluency when slightly intoxicated. Alcohol boosts GABA, the brain’s main inhibitory neurotransmitter, whereas Baclofen directly stimulates GABA-B receptors in the brain.