I have had some success with 'blueberry' indica strains (named for their fragrant characteristics I believe). I can be incredibly productive with this in the right environment (quiet, minimal interruptions, physically comfortable). But it's harder to shift focus and social interaction (even with intimates) is more of a chore. I don't know that it helps with adhd so much as alleviating anxiety enough to let me focus on what I want to think about.