i.

Catatonia is a psychomotor syndrome characterized by concurrent emotional (anxieties, depression, mania), behavioral (mutism, stupor, stereotypies, perseveration), and motor (akinesia, posturing, catalepsy) alterations (Kahlbaum 1878; Gelenberg 1976; Taylor 1990; Fink et al. 1993; Northoff 1997) that may occur in variety of different diseases but predominantly in schizophrenic or affective psychosis (Taylor 1990; Northoff 1997, in press). Despite severe motor anomalies (akinesia, posturing), subjective experiences in catatonic patients are not dominated by feelings of an inability to move, as is the case in parkinsonian patients, but rather by an inability to control anxieties, which, in addition, distinguishes these patients from noncatatonic psychiatric patients with either schizophrenic or affective psychosis (Northoff et al. 1998). The importance of emotional alterations in catatonic patients is further underlined by the dramatic therapeutic efficacy of lorazepam, a benzodiazepine with strong anxiolytic properties (Rosebush et al. 1990; Northoff et al. 1995a; Bush et al. 1996a, b). Pathophysiological mechanisms of psychomotor alterations in catatonia remain, however, unclear. Studies of regional cerebral blood flow (rCBF) in resting conditions showed alterations in the medial and lateral prefrontal cortex in catatonic compared to noncatatonic psychiatric patients (Satoh et al. 1993; Liddle 1994; Galynker et al. 1997; Northoff et al. 1999c, 2000ft). Investigation of cortical motor structures during sequential finger opposition in FMRI showed no major alterations in activation of cortical motor structures such as the supplementary motor.