Rapid vigilance and episodic memory decrements in Covid-19 survivors

Question for medical science folks. I realize that having a messy cohort of participants is normal, but with the estimates that we’ve only positively identified 10-20% of COVID cases, and with antibody tests having a wide margin of error, what are the chances that a non-trivial portion of the “control” group were also post-infection?

I mean fuck I know correlation doesn’t equal causation but cmon… this draws attention to poor mental health following COVID. Has no one seen the developed world lately? It’s fucking terrible for mental health. The news tells you the sky is falling every five minutes, the loudest and most observable voices are full of spite and anguish. For god sakes they shut everything down. Business owners have their livelihoods stolen from them, poor and middle class can actively observe those above them keep going up while they stay put. Children cannot be allowed around around other children because adults who have already lived their lives get to choose what’s best. In general the rules being made in the past 2 years have been vehemently opposed to maintaining peoples mental health. I know this study was not exactly opinionated, but the world shitting out and then people are also exhibiting symptoms of poor mental health…Quite the fucking coincidence if you ask me.