Longitudinal studies have also demonstrated that higher levels of serum IL-6 and CRP in childhood are associated with increased risk of psychotic disorders and depression in early-adulthood, consistent with MR studies (Khandaker et al., 2014, 2018; Metcalf et al., 2017; Perry et al., 2021a, 2021b). The gene discussed is IL6; the disease is major depressive disorder.