Background. In patients with schizophrenia, passivity delusions are characterized by a difficulty in determining the agency of purposive actions. Neuropsychological and functional neuroimaging data suggest that passivity delusions are associated with dysfunction of the parietal lobe association cortex.
Method. Cortical volume calculated from magnetic resonance imaging data in a group of 12 patients with schizophrenia characterized by motor passivity delusions was compared statistically with the cortical volume of 11 patients without passivity delusions.
Results. Reduced cortical volume was observed in parietal and frontal association cortices in the passivity group.
Conclusions. These data provide direct evidence for the involvement of the parietal lobe in the pathophysiology of passivity delusions in schizophrenia.