I actually play the game as my mother died from Pick's Disease and I have a sister suffering from dementia and is in an assisted living dementia wing. My hope is the math involved in the game will keep me sharp.
Years ago now - I postulated that WGT could potentially be used as a form of "evaluation" or potential sign of skills declining. Hand eye reflexes, timing, etc.
The only challenge I see with that now - is the game has built in random variance that can even make a fully competent person feel inept at times. One minute you are playing near perfect and the next you can't make a birdie because the gaming algorithms have decided to "test" or maybe even evaluate your play for cheat software - as such - nothing you do can overcome the messed up variance you will get at times.
So - the only thing I would caution you now - is don't take the game as always being a sign of your own progress or decline - you would need to look at overall and longer trends versus and short time scoring swing fluctuations. If you doubt that look at the number of high level players WD in 1000 credit RG's they are fully competent but get either BS winds or wonky variance that leaves them frustrated to the point of WD'g.
However, if you have a family member or fellow club member you play with regularly in multi player games they may be able to gently prod you to check in with a doctor because catching something early is much better than catching it later when less can be done to delay or possibly offset some of the cognitive decline.
I share this from observations and having family members with debilitating diseases, not as a medical professional or anything - just a concerned person hoping to offer some additional insight.
Yes, I still agree that the math and thought process involved can help keep the mind active - but the game is not designed for mental health or physical well being - could it be? Yes, but in it's current form - it is more designed to seek profit and induce variance that will throw off even the best in the game at times, so that hinders anyone seeking to evaluate their day to day playing ability which could possibly swing more than what is normal.
I have even had some chats with friends that are very competent at the game - yet WGT has frustrated them to the point they feel like something is wrong - and they know what they are doing they have demonstrated it for years, but the game just seems to force people to play poorly or poorly by their standards at times.
Because of this, I think the game at times can further frustrate and antagonize even healthy people because they go from feeling completely competent to being made to feel incompetent with swings of variance that prevents them from scoring as well as they normally would - and that is what WGT supposedly seeks to model - the scoring swings experienced in real golf - regardless of how competent you get.