Furthermore, elevated CSF levels of IL-8 were observed in individuals with schizophrenia [175], schizophrenia spectrum disorders [176,177], bipolar disorder (BD) [178], major depressive disorder (MDD) [175], in adult patients with autism spectrum disorder (ASD) [179], and patients with Parkinson’s disease and dementia (PDD) [180]. Here, CXCL8 is linked to major depressive disorder.