I can't help much on the day to day because I only get one day ketamine infusions. However, I get a huge dose during that one four hour treatment. You are not responsible for how you act or what you say while under treatment IMO. It's common for people to act crazy. More people will probably chime in here with stories.

The second thing is to be diagnosed at only four months into it with useful things already being done to treat it is like a miracle most of us never experienced. He actually has a chance at recovery or a good remission.

Hang in there. Don't take him too seriously except for the suicide stuff and then make sure he's monitored safe from his threats.