The Mind Game (1980)

Down on his luck Hollywood director's down on her luck actress wife gets taken over by a mind game cult like Est or Scientology called Transformationalism.

She disappears into the bowels of Transformationalism, he's determined to "rescue" her to the point where pretends to be taken over too. Is he or isn't he? As he delves deeper and deeper (or higher and higher depending on what who believes), he's no longer sure either.

A novel about the power of cults, show biz and cults, and just maybe the nature of "reality" assuming there is one.

One of the real such cult took a certain offense with the author, there was a mysterious burglary with nothing of value taken, a few other such mind games. Long out of print in English though still around in a few other languages.

Que pasa?
Quien sabe?
Save to read about it in a novel than publish one.