“…Finally, two studies investigated T-cell subpopulations [ 111 , 120 ]. Among the included studies, 13 studies [ 10 , 13 , 26 , 34 , 98 , 111 – 113 , 115 – 117 , 119 , 120 ] found a significant association between inflammatory markers and COVID-19-related depressive symptoms, while three studies did not find any statistical association [ 110 , 114 , 118 ]. Specifically, post-COVID-19 depressive symptoms were found to be associated with NLR in four studies [ 112 , 115 – 117 ], with CRP in four studies [ 34 , 98 , 113 , 115 ], with systemic inflammation index (SII) in three studies [ 10 , 13 , 26 ], with the neutrophil count in two studies [ 115 , 117 ], and with IL-6 in two studies [ 34 , 113 ].…”