I find the best way to deal with nuttiness is give standard program replies and just talk program. That way it avoids getting into anything personal which won't be constructive and throws water on the crazy flames.
Thankfully we don't live together so while he was talking some illogical nonsense last night I simply said "You are still living an addict life." and then he got mad and hung up. So that ended that conversation and I didn't call back to continue the nuttiness. So when we spoke this morning it was about something entirely different.
Ngaire