SPD can definately be helped by a qualified OT (disclaimer- I am an OT!). I have seen OTs do amazing things with kids with SPD. As was insinuated in a previous post, there are some in the medical community that don't believe SPD exists. But trust me, it does. There are also that believe giftedness is not an issue! SPD is also very prevalent in the gifted population. When my daughter started at her private school for gifted kids, I could not believe the SPD behaviors I saw on the playground the first day I picked her up from school- so much more than at a typical school! There are more OTs in some areas that practice in SPD than others so you may not have the wait time that others have indicated.
