I don't know; I've read the marijuana causes worse problems over the long run for those with ADHD despite some help here and there at first (which isn't consistent over time). It is addictive and the addiction isn't fun to deal with. I guess it is like alcohol seeming like it helps with a depression but is a depressor itself and ultimately makes things worse for those with anxiety or depression. And medical marijuana hasn't been approved for ADHD for any state that I know of; a doctor can't just prescribe it for whatever he feels like, only a small list of some illnesses (usually fatal anyway, like some cancers, AIDS, etc.)

Read this: http://home.iprimus.com.au/rboon/ADDandMarijuana.htm

It has actual studies/references. There's a lot pro and con I read on the Web but I didn't find any actual doctors/research studies that were all for it. One newspaper article said it had helped an ADHD student drive better on one test but he was being tested because he had a zillion tickets and run-ins with the police! Apparently the active ingredient does screwier than the Strattera or Ritalin; acts on more than one important thing and you get mood changes, etc. Not good to add to the problems you have already?