Conspiracy Theories

My husband listens to the radio program "Coast to Coast" almost every night. He is a person who is very easily deceived, not someone I would say is always the greatest judge of character.

So almost every day my husband says the same thing. "There was a very intelligent guest on Coast to Coast last night. The (guy/woman) really knew his stuff. And I believe him." ...Then he delves into some conspiracy theory. I mean, about EVERYTHING imaginable. I believe that some conspiracy theories might well be true. But every one? No. Elvis killed by the mafia...Janis, Jimi, and Jim killed by the CIA...Every streak of white in the sky is a chemtrail (he won't STOP about this one)...our power grid is definitely going down in the near future and we should invest money in stockpiling food and water...Bigfoot is an astral being that has been captured by the World Oligarchy...

I mean, it gets tiresome. My husband has severe OCD and is a major hoarder. So, he definitely has mental illness (which he refuses to treat because "big pharma is trying to control the population"). He definitely shows sighs of MCI (mild cognitive impairment, which is something that can indicate early dementia). At what point does the belief in conspiracy theories become a true form of paranoia?