Associating Psychotic Symptoms with Altered Brain Anatomy in Psychotic Disorders Using Multidimensional Item Response...

Area of Science:

• Neuroscience
• Psychiatry
• Brain Imaging

Background:

• Reduced cortical thickness is observed in psychotic disorders.
• The precise relationship between cortical thickness and clinical symptoms remains unclear.

Purpose of the Study:

• To identify neocortical regions where clinical psychosis manifestations correlate with cortical thickness.
• To investigate the link between specific symptom profiles and regional brain structure.

Main Methods:

• Utilized multidimensional item response theory on a large cohort (N=1919) from the Bipolar-Schizophrenia Network for Intermediate Phenotypes.
• Measured regional cortical thickness using FreeSurfer on structural MRI scans.
• Assessed individual symptoms using the Positive and Negative Syndrome Scale, Montgomery-Asberg Depression Rating Scale, and Young Mania Rating Scale.

Main Results:

• Identified a cluster of contiguous cortical regions with thickness inversely related to psychosis symptom severity.
• These regions span heteromodal association cortex, including temporal, parietal, and frontal lobes.
• No significant association was found between reduced cortical surface area and high psychotic symptoms.

Conclusions:

• A contiguous network of neocortical regions in the temporal, parietal, and frontal lobes is critically involved in psychosis expression.
• Cortical thickness in these specific areas may serve as a neural correlate for psychosis symptom severity.