Question: My 29 year old son is exhibiting extreme anger that is poorly controlled. He was diagnosed as ADD about 18 months ago. He takes Vyvanse. I am unsure of dosage. We have a family business and he is preparing to purchase it along with his older sister. He is accusing her of being manipulative and domineering. She is a driven Type A personality, and detail and goal oriented. He is of higher than normal intelligence and a "big picture" synthetic thinker. (Actually, an excellent team). She does have a tendency to say hurtful things when tired or "threatened". He sees us (his parents) as supporting her over him in business decisions. He recently took a minor disagreement from minor to monumental, assigning meaning where there really wasn't any and becoming agitated and angry.
He does consume small amounts of alcohol (learned by experience that he can't drink more than small amounts occasionally). He is in good health otherwise, but has a slender build. He does not accept criticism, he hold grudges and brings up past incidents often and childhood slights. He does not hit people, but has destroyed things like phones. He is socially astute, comfortable in crowds or presenting to a group. He is aware of and recognizes an occasional "victim mentality" in himself. He has a number of higher level credentials in our line of work (financial) that place him well above other age cohort peers. He has some trouble meeting deadlines.
I feel that his perceptions are somewhat skewed. I sense that he needs more than talk therapy, which he has had. His maternal grandmother (my mother) is schizophrenic. She was diagnosed in the mid 1970s and her disease is still active. She is 85 and takes Risperdal and although has some flattening of affect, is probably as functional as she has ever been. She has a Master's Degree (obtained while un-medicated),is musically talented and accomplished and taught Elementary Music until her disease progress made that untenable. She then taught private piano lessons until age 75. In other words, she coped fairly well punctuated by "incidents" and then responded very well to medication. Any attempt to take her off meds has been a disaster. I assumed her history is relevant. No other mental illness in family, although my husband had anger management issues when the kids were growing up (verbal).
I would like suggestions for further treatment. I would like to know if alcohol is totally contraindicated with Vyvanse. I would like a sense of the advisability of my two children running a business together. Would that be exceptionally stressful for him. At 29, is there still a chance of breaking with schizophrenia? Can stress induce that?

I just want to make sure this online diagnosis and my email are confidential. I see some Q/A on the website.... I would never want this communication available to anyone else.