I don’t want to claim that meditation is the answer to every mental health problem. But it’s helped me, and I sometimes recommend trying it, particularly mindfulness. (And you can do mindfulness seated and at rest, or walking, or any number of routine activities—just not driving, please!).
I’ve heard a number of people say “But I just can’t still my thoughts! My mind is racing, and I give up feeling more defeated than ever!”
Mindfulness is not about forcing your mind to stop thinking. Rather, it’s about becoming aware of what you’re thinking… and then letting the thought go.
I’ve linked an article I found recently that explains it really well. TLDR (though it’s worth reading in full): A Tibetan Buddhist monk, chosen as the reincarnation of a revered predecessor, absolutely loathed being a monk as a teenager. He was angry, snarly, irritated, and a great vexation to his teachers. Angry thoughts constantly interrupted his meditation practice (and everyone around him).
One teacher gave him some advice: when you meditate, don’t be like a dog; be like a lion.
“When you throw a stone at a dog, what does he do?” he asked.
“The dog chases the stone,” I replied.
He said that was exactly what I was doing, acting like a dog—chasing each thought that came at me…
“When you throw a stone at a lion,” he continued, “the lion doesn’t care about the stone at all. Instead, it immediately turns to see who is throwing the stone. Now think about it: if someone is throwing stones at a lion, what happens next when the lion turns to look?”
“The person throwing the stone either runs away or gets eaten,” I said.
“Right you are,” said my teacher. “Either way, no more stones!… Instead of chasing the anger, grabbing it, and holding on, just be aware. Just be very gently aware of the anger instead of getting involved. Don’t reject it, but don’t dwell on it either. Just turn your attention to look gently at the thought. At that moment of turning inward to just observe, the thought will dissolve. At that moment, just exhale and rest.”
Well—could be any one of a number of things. Article clearly states (and I'll second) that this isn't a comprehensive checklist that points only to dementia.
I'm not going to say what else it might be, as there are so many possibilities. That could generate a raft of options for a total hypochondriac meltdown set of things to worry about.
I will add that partner's medical & psych team ran through a whole bunch of other options, and none of the obvious meds, counseling, physical tests seemed to help or point anywhere else.
It's a list to pursue seriously with healthcare providers, though.