--Neuroleptic malignant syndrome (NMS): Malignant catatonia and NMS are both life-threatening conditions that share many of the same characteristics including fever, autonomic instability, rigidity, and delirium. Lab values of low serum iron, elevated creatine kinase, and white blood cell count are also shared by the two disorders further complicating the diagnosis. There are features of malignant catatonia (posturing, impulsivity, etc) that are absent from NSM and the lab results are not as consistent in malignant catatonia as they are in NMS. Some experts consider NMS to be a drug-induced condition associated with antipsychotics, particularly, first generation antipsychotics, but it has not been established as a subtype. Therefore, discontinuing antipsychotics and starting benzodiazepines is a treatment for this condition, and similarly it is helpful in catatonia as well.