Yes, at my job I work with people with intellectual or developmental disabilities too. A lot of them have mental illnesses in addition, and they are much less likely to get therapy, and more likely to get medicated (not always appropriately). I'm trying to convince staff that Xanax is for anxiety, and is not a magic anti-aggression pill (that doesn't work too well as such). And I'm still not sure how they can decide that someone who is nonverbal has hallucinations. Maybe he just likes staring at the ceiling, or maybe he noticed a cobweb.