Drug therapy worked very well for me but had some devastating side effects. I used a 2 drug combination of Clonazepam and Citalopram. You can find many studies done on these types of drugs (anti anxiety and an SSRI combination). I used these drugs for 6 years and totally changed how I felt about my speech. I could ask an employee at a store where something was without it being an issue! I could order Starbucks in the drive thru without issue. I was very fluent and had NO anxiety about going into speaking situations. Things were good, so I thought. My speech was good but in that time frame these drugs had ruined my marriage and changed who I was. These are very powerful drugs that can do some very good things but you never get anything for free. There are side effects. I have been off these drugs now for 8 months and have had a tough time with my speech coming off the drugs due to the other issues with coming off of an SSRI (look that up, not very pleasant). My speech has returned to where it was before all of this experiment but I now feel that I have come to terms with my stutter finally after turning 50 this year. This is just my experience yours may vary.