CHAPTER 40: Pellagra: Psychiatric Manifestations

Pellagra is a deficiency disease associated with low levels of vitamin B3 (niacin) and/or tryptophan. Gasper Casal first described the disease in 1972, when he observed that patients with pellagra were all poor, subsisted mainly on maize and rarely ate fresh meat. The clinical picture is a combination of multisystem alterations typically involving gastrointestinal, skin and central nervous system abnormalities. In this chapter, we organize the psychiatric features into three categories: (a) Common early psychiatric features (b) Cognitive deficits (c) Psychotic features. Common early psychiatric features seen as irritability, poor concentration, anxiety, fatigue, restlessness, apathy and depression. The cognitive problems observed generally include impaired concentration, memory impairments and, in severe cases (pellagraoid encephalopathy), confusion, delirium and coma. The psychotic features present in three forms which are (a) schizophreniform, (b) manic depressive types and (c) anxiety and depressive disorders. We also discuss the neurophysiological mechanisms of these psychiatric manifestations.