Catatonia: neuroleptic malignant syndrome

The relationship between catatonia and neuroleptic malignant syndrome (NMS) has, in the last three decades, generated considerable interest and controversies. This article provides a critical overview of our understanding of the relationship between the two enigmatic syndromes. It examines various conceptualizations of NMS, published data supporting a close relationship between the two syndromes, hypotheses proposed and controversies generated regarding how the two are related, and the clinical and pathophysiological implications of the relationship.