I am so very sorry for your pain, dear.
As a long-term recovering alcoholic/addict (21+ years), I have watched many fall back into the active disease, and it is posts like this that remind me how important my recovery is to me.
As for what his psychiatrist has prescribed him in the past, it is up to your AH to be honest with all his medical providers. I find that being rigorously honest about my alcoholism/addictions with my medical providers (including a psychiatrist) is an integral part of my recovery.
Please be gentle with yourself, and know that you are among friends.