Delusions linked to claustrum, insula volume in schizophrenia patients
MedWire News: Results from a US study suggest that delusion severity in patients with schizophrenia is significantly associated with left claustrum and right insula volume.
"With the advent of neuroimaging techniques, attempts have been made to correlate symptoms of schizophrenia with brain structure and function in order to better characterize the pathophysiology of schizophrenia," comment Nicola Cascella (Johns Hopkins University School of Medicine, Baltimore, Maryland) and team.
"The insula/claustrum region may be critical to the experience of delusions and more careful scrutiny of the claustrum in relation to schizophrenia appears warranted," they add.
Cascella et al investigated associations between cerebral gray matter (GM) volume and the severity of positive symptoms, particularly delusions and hallucinations, in 43 adults with schizophrenia who were aged between 19 and 56 years.
All of the participants underwent magnetic resonance imaging (MRI) of the brain, and the severity of delusions and hallucinations was assessed using the Scales for the Assessment of Positive Symptoms (SAPS). These symptom-severity tests were performed within 48 hours of the MRI scans.
Overall, 49% of participants were suffering from hallucinations (mostly auditory) and 70% from delusions at the time of their MRI scans, the researchers note.
After correction for multiple comparisons, the researchers found that scores on the SAPS delusion subscale were significantly inversely correlated with left claustrum and right insula GM volume.
There were no significant correlations between SAPS hallucination subscale scores or SAPS global rating scores and GM volumes, after correction for multiple comparisons.
Cascella and team conclude in the journal Schizophrenia Research: "Our findings suggest that structural differences in the insula and claustrum might contribute to positive symptoms in schizophrenia, specifically delusions.
"These findings emphasize the need to develop a better understanding of the role and function of the claustrum and insula in healthy and schizophrenic populations."
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By Mark Cowen