Psychosis with vitamin B12 deficiency and increased extrapyramidal side effects: A case report

Vitamin B12 is a methyl donor important for the continuity of neuronal metabolism. Deficiency in vitamin B12 has been associated with a variety of neuropsychiatric pathologies that include extrapyramidal symptoms such as mood disorders, depressive disorder, delirium, and paranoid psychosis. Extrapyramidal symptoms are also associated with factors such as gender, age, and the presence of a mood disorder. Novel generation antipsychotics are less likely to cause extrapyramidal symptoms than typical antipsychotics due to their selective anti-dopaminergic action and antagonistic effects on serotonin receptors. The present case report describes a patient with psychosis in which a vitamin B12 deficiency not only complicated the treatment of extrapyramidal symptoms, but also tended to increase them.