My son is considered non-verbal and DOES have Apraxia. Our SLP works wonders with him. Has your SLP implemented a Vocal Imitation Program or Echoics yet? It's very helpful. Especially when they do have a lot of sounds and some words, or approximations of words. :D

YES! My 3 year old says less than half a dozen words, but does try to repeat words/ sounds. His speech therapist calls it oral apraxia. Is he in speech therapy? Ours has given us about 8-10 different mouth exercises that we work on thru out the day to help strengthen his jaw/ mouth muscles. Call me crazy, but after religiously doing these I noticed him trying more sounds/words within the week and the exercises were getting easier for him which proves that the jaw is getting stronger.

You're not alone on feeling depressed over this, trust me! I use to tear up if we were out shopping and I saw little kids having conversations with their moms. Yes it sucks not to have those moments (yet), but working with him everyday and seeing improvements I know there is light at the end of the tunnel and I look forward to having a "verbal" conversation with him soon.

Also I find that most school SLP are very open to meeting with families to talk about the things they are working on in school. I think they rarely feel they are as involved/important as the teacher, but of course they are and they are experts who usually are very willing to share. They like progress too and they know they are more likely to see it if home is working on the same things the same way as well.

I would say try (official) PECS (pecs.com) this will help him communication even with motor issues. And has a good success rate in supporting verbal language development as well.

I would recoomend finding a private slp who specializes in apraxia.. They are out there you just might have to look. Apraxia is a complex issue, and not all slp have the particular training to treat apraxia. There are specific protocols used for children with apraxia that allow for their growth but there needs to be alot of consistency and follow through in home and at school as well. You can certainally discuss your concerns with the school slp but more than likely they can not diagnose, you will have to find a private to diagnose..