Well, I've been on ADT + Apalutamide (same family as Enzalutamide/Xtandi) for nearly 4 years now, and I don't feel remotely like a drooling idiot, if that's any comfort. I can still solve hard sudokus in ink without pencil marks, read books in several language, remember small details of conversations weeks or years ago, design complex databases and computer programs, memorize an hour of classical guitar repertoire (just this year), and keep track of all the details my own long-term prostate cancer treatment. I also went up in a Cessna with a flight instructor (I lost my own aviation medical because of the cancer and spinal injury), and he confirmed that I haven't lost any of my stick-and-rudder stills in the cockpit, either.

I'm not writing this to brag (I'm Canadian, after all), but I thought I'd put it all out there just this once to help allay any fears about ADT always destroying cognitive ability. I've had zero cognitive decline so far. I know not everyone's as lucky, but if early signs of brain fog do show up (as happens occasionally) he can always choose to stop ADT then.