As someone with a normally active social life, I can attest that I have felt unfamiliar levels of depression and isolation over the past year. It was particularly bad when I had to isolate. Those feelings haven’t entirely gone away.
As someone who has the self-awareness to identify why I feel the way I feel, I can safely say they’re due to COVID restrictions rather than having had the virus.
If I took a non-contextual test I’m pretty certain I’d end up in that 30 odd percent.
But this is anecdotal so it doesn’t count.