IL6 and major depressive disorder: In a study of 134 students (n = 76 with internalizing disorder, n = 58 without internalizing disorder) aged 10–17 years conducted by Cristiano Tschiedel Belem da Silva and colleagues in Brazil, students with internalizing disorders, including MDD, generalized anxiety disorder, separation anxiety disorder, social anxiety disorder, or panic disorder showed significantly higher IL-6 levels than students without an internalizing disorder [12].