Introduction

For over two centuries, the manifestations of catatonia have been given individual names as one author after another identified features that they considered unique. Whether each form is a distinct entity or a variation of a common pathophysiology is not clear. The differences in approach reflect personal attitudes, with the authors divided into “splitters” or “lumpers.” We are among the “lumpers.” The clinical conditions with a prominence of the classic catatonia motor signs in patients with disorders in mood and thought, and that respond to anticonvulsant and sedative treatments, reflect a common endophenotype. Despite the variation in overt forms, we think it useful to approach these diverse disorders as sharing a common brain pathophysiology.

Syphilis offers an analogy. A spirochaete infection is the common pathology with the clinical diversity depending on the organ that is involved and the severity and duration of the infection. The expressions of syphilis are so varied that the disorder has been called “the great imitator.” The different forms respond to the same treatments, however, strengthening our belief in a common pathology (see Quetel, 1990). In like fashion, we see the different expressions of catatonia as due to a common brain pathophysiology. The etiologies differ, but the commonalities in expression of motor signs and the response to treatment brings these threads together.