effects of b vitamins on symptoms and cognitive functions in schizophrenia: a randomized, double-blind, placebo-controlled clinical trial

Objective: schizophrenia which is a chronic disabling burdensome psychotic disorder has been treated with different antipsychotic medications. some studies have reported a possible correlation between deficiency in minerals, nutrients and vitamins — mainly group b vitamins — and the development of schizophrenia. in the present study, we aimed to examine the effect of the b vitamin group as an adjuvant treatment to antipsychotics in individuals with chronic schizophrenia.method: in a randomized, double-blind clinical trial study, involving two groups of 25 patients with chronic schizophrenia, we compared the effects of a 12-week adjuvant treatment with a combination of b vitamins — b1 (15mg), b2 (15mg), b6 (10mg), b12 (10µg) and nicotinamide (50 mg) — with a placebo. the impact on negative, positive and cognitive symptoms of schizophrenia was assessed for both groups before the intervention (t0) and at 4, 8 and 12 weeks after the intervention (t1, t2, and t3, respectively).results: following the treatment, negative symptoms scores decreased in the treatment group at 12 weeks following the beginning of the treatment (f (4, 45) = 464.7, p < 0.0001). although a trend toward improvement in positive symptoms and cognitive scores was seen, these changes were not significant.conclusion: our results suggest that selecting the group b vitamins as an adjuvant treatment to the antipsychotics may have beneficial effects on improving negative symptoms of patients with chronic schizophrenia.