The effects of pharmachotherapy on serum folic acid and vitamin B12 levels in patients with schizophrenia, bipolar disorder and major depressive disorder

摘要

Objective: Folic acid and vitamin B12 are essential cofactors in several biochemical pathways that are critical for neurobiological and hematological functions. Vitamin B12 and folate deficiencies are reported in schizophrenia and depression patients but there are only a few studies investigating the effects of the treatment on serum folic acid and vitamin B12 levels. This study aimed to investigate serum folic acid and vitamin B12 levels in patients with depression, schizophrenia and bipolar disorder and the effects of the drug treatment on these vitamin levels. Method: Twenty-six schizophrenia, 16 major depressive, and 47 bipolar (manic, depressive or mixed episode) disorder inpatients diagnosed according to DSM-IV criteria and 21 healthy controls were included in the study. Serum vitamin B12 and folic acid levels were measured before the treatment. The patients received the treatment at therapeutic doses for 5 weeks. Fifteen of the schizophrenic patients were treated with atypical antipsychotics including risperidone, olanzapine, quetiapine and 11 of them with typical antipsychotics (haloperidol or zuclopenthicsole). Bipolar patients received mood stabilizer and antipsychotic and/or antidepressant according to their present episode. The patients with major depressive disorder were treated with various antidepressant drugs. Serum vitamin B12 and folic acid levels were measured again in all patients after five weeks. The same measurements were performed only once in the controls. Results: Serum folic acid and vitamin B12 levels were not significantly different among the patient groups and the controls in pre-treatment. In schizophrenic patients, serum folic acid levels were significantly reduced after typical antipsychotic treatment compared to those in pretreatment and to those of the controls while they did not change after atypical antipsychotic treatment. Bipolar patients who received lithium had lower serum folic acid levels in post-treatment than in pre-treatment. There was a negative correlation between serum folic acid levels and severity of depression in the patients with major depressive disorder. Conclusion: The results of the study suggest that serum folic acid and vitamin B12 values in schizophrenia, bipolar disorder, and major depressive disorder did not differ from healthy controls. However, it seems that some drug treatments might lead to a decrease in folic acid levels. Nevertheless, further studies are needed to confirm the effects of specific drug treatments on these vitamins.