Where is he getting speech therapy? Is it through the schools or is it private? He's been getting speech therapy for 6 years and it's not helping, it's time to change to something else. Full disclosure, I don't feel that the school systems are adequately funded or able to support disabilities. Finding the right SLP is the big challenge. There's a lot of therapist out there that have good intentions but treating a person with a stutter is not in their skill set and they don't have specialization in the subject. If he wants fluency, it's going to take work. At 14 a lot of young men hit the weights and they see dramatic improvement by lifting an hour a day. Fluency can be very similar to that. An hour a day of practice can have a dramatic impact. My success with fluency came when I was in my '20s and I was putting at least 30 minutes a day into practice. Was seeing my speech therapist one to two times a week to direct my progress. I was seeing the same speech therapist at 14 but I wasn't willing to do the work and didn't see much progress at that time in my life. I had a significant break from therapy from my mid teens until I returned in my twenties. I am not an expert. I'm not trained in the field. Everything I'm sharing is purely anecdotal. It's really important that he stay true to himself. Too many of us withdraw or get salty about our situation. These negative responses just reinforce isolation and other problems that stutterers often encounter. The biggest challenge is finding the qualified help that can guide your son to fluency.