B₁₂ deficiency and psychiatric disorders: Case report and literature review

Although an association of psychiatric symptoms with vitamin B₁₂ deficiency is well accepted, the incidence and nature of these symptoms is not established. To help illuminate the natural history of this illness the authors review the literature regarding psychopathology associated with B₁₂ deficiency and examine 15 cases, including one of their own, that meet specified criteria for B₁₂-responsive psychosis. In the accepted cases the most common psychiatric symptoms were organic brain syndrome, paranoia, violence, and depression. Several of the patients were not anemic and had no neurologic deficit. Examination of blood smears or obtaining of serum B₁₂ levels should be considered for patients with the symptoms described.