White matter abnormalities and neurocognitive deficits associated with the passivity phenomenon in schizophrenia: a diffusion tensor imaging study.

The passivity phenomenon is a distressing Schneiderian first rank symptom in patients with schizophrenia. Based on extant data of functional and structural cerebral changes underlying passivity, we sought to examine cerebral white matter integrity in our subjects. We hypothesised that the passivity phenomenon would be associated with white matter changes in specific cortical (frontal, parietal cortices, and cingulate gyrus) and subcortical regions (thalamus and basal ganglia) and correlated with relevant neurocognitive deficits, compared with characteristics in those without the passivity phenomenon. Thirty-six subjects (11 with passivity and 25 without passivity) with schizophrenia were compared with 32 age-, gender- and handedness-matched healthy controls using diffusion tensor imaging. Neuropsychological testing was administered. Patients with passivity were associated with increased fractional anisotropy within the frontal cortex, cingulate gyrus, and basal ganglia and decreased fractional anisotropy within the thalamus when compared with patients without passivity. Within patients with passivity, fractional anisotropy in the frontal cortex correlated with the age of onset of illness and neurocognitive deficits related to attention and executive functioning. The findings suggest distributed involvement of cortical and subcortical regions underlying passivity and support the notion of neural network models underlying specific psychiatric symptoms such as passivity.