TNF and schizophrenia: Therefore, the aims of our research were (1) to compare differences in the TNF-α levels among first-episode drug-naïve (FEDN) patients with schizophrenia, chronic patients, and healthy controls; (2) to assess TNF-α changes in FEDN patients before and after treatment with risperidone for 12 weeks and analyze the correlation between the TNF-α levels and psychiatric symptoms in patients with schizophrenia; and (3) to analyze the possible existence of sex differences in the TNF-α levels in patients with schizophrenia.