Hi Shari,
I'd probably find a neuropsych for this. OTs are the main people who diagnose SPD; but they tend to overdiagnose it (attributing everything to sensory when it may or may not be sensory in origin), whereas a neuropsych will be qualified to look for a broader range of issues including but not limited to sensory ones.
My feeling is, find out all you can sooner rather than later about what you're dealing with, so you can target your efforts most effectively.
HTH, good luck with Mr. Helper-- he sounds sweet and also like he's had a tough lot to deal with.
DeeDee
