Many people with autism suffer from Sensory Integrative Dysfunction. There is a new clinic that has received great reviews. It's local here in Brooklyn (in Bay Ridge) called Sensory Freeway. They mostly deal with the younger population (from ages 6 months to 10 years); however, there are licensed occupational and physical therapists on staff that may at least steer you in the right direction. I mention the sensory issues because you mentioned how your brother could drink water 'till the point of throwing up. Those of us, with sensory functions within normal limits, are aware when our stomachs get full of drinks or food. Sensory Freeway's address is 9306-4th Avenue, Brooklyn, NY 11209. Their phone number is (718) 238-7451. Their web site address is www.sensoryfreeway.com I hope this helps.