according to this study going through covid results in statistically significant decreased intelligence after recovery, even if there were no respiratory symptoms.

can someone quickly refute this study? don't wanna read through the whole thing. did they even make sure to only include people who already recovered, or just mixed in those who were actively ill while taking the second test?


https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(21)00324-2/fulltext