Interestingly, although short-term olanzapine treatment exhibited significant improvements in cognitive function in schizophrenia patients (44), previous studies found that long-term clinical use of olanzapine causes adverse metabolic effects, including weight gain and alterations in lipid and glucose metabolism, which are associated with a state of chronic and low-grade inflammation, and consequently reduce levels of brain-derived neurotrophic factor, resulting in neurological damage and secondary cognitive impairment (45, 46). Here, BDNF is linked to schizophrenia.