Thus, adolescents presenting with anxiety and depression display higher blood levels not only of pro-inflammatory cytokines like interleukin (IL)-1β, IL-6, and interferon (IFN)-γ but also of anti-inflammatory cytokines such as IL-1 (Henje Blom et al., 2012; Gabbay et al., 2009a, 2009b; Howe and Lynch, 2022). This evidence concerns the gene IL1B and major depressive disorder.