The effect of ascorbic acid as a supplementary treatment with risperidone in controlling the symptoms of schizophrenia: A double-blind, placebo-controlled clinical trial

Background and Objective: Considering the hypothesis of the effects of the use of antioxidants such as ascorbic acid on the improvement of oxidative stress induced by schizophrenia, the present study was designed to investigate the effect of ascorbic acid as an adjunctive therapy with risperidone in controlling the symptoms of schizophrenia. Materials and Methods: This randomized clinical trial was conducted on patients with schizophrenia admitted to Tehran's Razi hospital of psychiatry in 2018. The patients were divided into control and intervention groups. The group treated with ascorbic acid received this drug daily at 500 mg twice daily and the placebo group received a similar drug, similar to ascorbic acid, at the same rate for 4 months. The PANSS (Positive & Negative Symptom Scale) questionnaire was used to determine the status of the positive and negative symptoms and the SCORS (Schizophrenia Cognition Rating Scale) questionnaire was used to determine the cognitive status at the end of weeks 8 and 16 when entering the study. Data were analyzed using paired t-test and Wilcoxon in SPSS 20 software. Results: The effect of ascorbic acid on the positive and negative symptoms of patients at the 8th and 16th weeks showed that after eight weeks of treatment, among the positive symptoms, conceptual disorganization, excitement, hostility and grandiosity, among the negative symptoms, blunted affect has had a significant improvement relative to before intervention. After 16 weeks of treatment, except difficulty in abstract thinking, all of the symptoms showed a significant improvement compared with the symptoms of the patients before the study. Compared to ascorbic acid, the effect of placebo on all of the positive and negative symptoms and other symptoms in most cases was not significant. Regarding the effect of ascorbic acid on the cognitive symptoms of patients in the 8th and 16th week, there was no significant difference in the few numbers of cognitive symptoms in the eighth week, although after eight weeks, overall cognitive symptoms were significantly improved (p<0.05). In addition, after 16 weeks of treatment, almost all of the parameters of the cognitive symptoms and the total of cognitive symptoms were significantly improved compared to the pre-intervention (p<0.01). Compared to ascorbic acid, the effect of placebo on cognitive symptoms in most cases was not significant (P >0.05). Conclusion: The results of this study showed that ascorbic acid, having its antioxidant effects after sixteen weeks of treatment, reduced the patients' positive and negative symptoms and their cognitive symptoms. Compared to ascorbic acid, the effect of placebo on cognitive symptoms and positive and negative symptoms was not significant in most cases.