IL6 and post-traumatic stress disorder: In our study, higher serum IL-6 levels were associated with a doubled higher risk of long COVID (OR = 2.05; 95% CI: 1.04–4.50) and, in particular, they were associated with a higher incidence of mobility decline (OR = 2.55; 95% CI: 1.08–9.40) and PTSD (OR = 2.38; 95% CI: 1.06–8.61).