No association between micrometer-sized particles in human cerebrospinal fluid and schizophrenia

The pathogenetic processes underlying schizophrenia are unknown, but the organic changes observed in the brain tissue of schizophrenic patients suggest the possibility of findings also in the cerebrospinal fluid (CSF) of patients suffering from this disorder. In a recently published study micrometer-sized spherical particles in CSF were isolated from significantly more schizophrenic patients compared to controls. The functional importance of these particles is unknown, but if replicated in independent study samples they could function as trait markers and spur further investigations. We analyzed CSF samples from five patients with a diagnosis of schizophrenia, nine patients with chronic pain syndrome and six healthy controls with scanning electron microscopy in accordance with the protocol described in the original report. Similar particles were identified as in the previous study, but they were not associated with disease status (P=1.00). It cannot be excluded that these divergent results are due to methodological differences, but presently the most parsimonious explanation would be that the original finding was a false positive result. More investigation is needed to clarify the source and relevance of these particles.