To The Editor: Max Fink, M.D., and Michael Alan Taylor, M.D., have put forward a strong case in favor of making catatonia a separate category in subsequent editions of the DSM. However, their assertion that the diagnosis of catatonia should be made by observing the patient’s response to the administration of lorazepam/amobarbital seems to be an oversimplification of the issue. It is correct that catatonic features have been shown to respond to the administration of these compounds. However, the assumption that "[t]he diagnosis may be confirmed by symptomatic improvement after the acute administration of a challenge dose of lorazepam or amobarbital" (1, p. 1875) seems to be an overgeneralization. Response to these agents by no means provides a definitive diagnosis of catatonia, and there is no evidence to support the use of these tests as confirmatory. Catatonic features are not specific to any one condition and can be observed in a variety of conditions. Some of these conditions might respond to lorazepam or amobarbital; for example, conversion disorders such as conversion mutism are associated with features that do resemble catatonia and do respond to the amobarbital assisted interview. In summary, it may be prudent to avoid the use of response to lorazepam/amobarbital as a confirmatory test for the presence of catatonia.

1.Fink M, Taylor MA: Catatonia: subtype of syndrome DSM (editorial). Am J Psychiatry 2006; 163:1875—1876