Choroid plexus calcification as a possible marker of hallucinations in schizophrenia.

Several studies suggest that disturbances of serotonin (5-HT) functions may be involved in the pathophysiology of hallucinations in schizophrenia. It is now well established that the choroid plexus (CP) is innervated by serotonin (5-HT) neurons, which may regulate its activity, and it is possible that decreased 5-HT functions may facilitate the process of its calcification. It is thus conceivable that calcification of the CP may be associated with hallucinations in schizophrenia. I studied in 18 chronic schizophrenic patients the association of CP calcification (CPC) size as ascertained from CT scan, to severity of hallucinations and, for comparison, to four other positive symptoms as well as global psychopathology score. Analysis of variance indicated that CPC size was specifically associated with hallucinations (p < .001) and none of the other psychopathology measures. These findings reveal a relationship between CPC and hallucinations in schizophrenia and suggest that the former may be a neuroradiological marker of hallucinations in the disease.