Hallucinations - he should also be checked for B12 deficiency, which can cause psychosis and depression. Does he have any risk factors, like family history of autoimmune disease, or vegetarian diet, or long-term use of acid-blockers like Tagamet etc.?
Also - does he take any prescription medications? I know there have been a few reports of Parkinson's drugs triggering compulsive gambling or other compulsive behaviors. Lipitor and other statin drugs have been associated (rarely) with odd behavior too.
