SPD shares more similarities to Narcissitic Personality Disorder than it does with ADHD -- not in terms of effect and imposition on other people, but rather in the lived experience of self and other, self and world. I don't think SPD (or NPD) are something you can medicate.
They're also kinda opposites. The cure for NPD is isolation and the cure for SPD is being around people (agreed-- neither are in pill form yet). They both have immutable internal status, but the narcissist's is very low while the schizoid's is very high.
The best example IMO of a cured narcissist is Larry Lawton, who faced a long period of isolation in prison. He's on Youtube.
If we're going that route, I think it's more likely we'll see clinical outcomes with therupeutic use of psilosybin or MDMA.
I don't think it is so much that the brain needs to be tweaked, but that experiencing self, other, and world in a different ways can transform those in a way that does not require ongoing medication.
