This is just my personal thoughts, but I feel like a scientifically sound dietary restriction that is effective at weight loss means people have a better body image. Body image would improve mental health for most people seeking out keto as a diet.

I welcome the research, but I feel like the reason is social rather than biology.

Plenty of studies showing mild brain inflammation can cause anxiety and ocd.

Keto reduces inflammation.

Not saying that’s the mechanism, but it seems plausible.