RESUMEN
In contemporary psychiatric classification such as the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, and International Classification of Diseases, 10th Revision, catatonia is classified as a subtype of schizophrenia and not as an independent disorder. However, catatonia does not seem to obey nosological boundaries and is seen with both affective and nonaffective psychoses. We conducted a chart review of patients to examine the nosological status of catatonia. Our data suggest that catatonia is a syndrome of varied manifestation possibly related to both affective and nonaffective psychoses with a subgroup independent of both. Further prospective studies examining the natural course are needed, which could have significant implications on future classificatory systems.