Aside from the idea that knowing what the issue is helps you be more tactical in solving it...
If it's Asperger's you may want to look into ABA or other treatments based in behavioral psychology that have been shown to improve autistic behavior. You would definitely want to get some kind of social skills training in place. The speech therapist might do this, but they may or may not be the right person for the job if it's an autism spectrum disorder. The OT may be helpful for some of the sensory-type things, but if there are social or theory of mind deficits, an OT is not usually equipped to work on those.
DeeDee
