TNF and major depressive disorder: Additionally, Pandey examined the levels of immune markers in the cerebrospinal fluid of 24 adolescents who died by suicide, and higher levels of mRNA and protein expression of IL-6, TNFα, and IL-1β were detected in the prefrontal cortex compared to healthy controls (56), although only 33.3% (8) of these victims had been diagnosed with depression during their lifetime, suggesting that inflammatory cytokines association with adolescent suicidal ideation is not dependent on depression.