The regulation of the amino acid homocysteine is dependent on the dietary intake of folic acid and other B vitamins. There is evidence for increased blood homocysteine in patients with schizophrenia, including those with first-episode psychosis (FEP), which is also associated with greater negative symptoms and poorer functioning.1-3 Furthermore, there is also evidence for decreased blood folic acid levels in patients with FEP, which are associated with greater negative symptoms.4 No previous studies have investigated the effectiveness of B-vitamins in patients with FEP.
https://www.psychiatrictimes.com/schizophrenia/vitamin-supplementation-first-episode-psychosis