Cortical Thickness Reduced in Schizophrenia Compared With Bipolar Disorder

There was no similarity in cortical thinning between patients with schizophrenia and psychotic bipolar I disorder.

Patients with schizophrenia show significant reductions in cortical thickness when compared with patients with bipolar disorder and healthy controls, according to research published in the International Journal of Bipolar Disorders.

Researchers examined the cortical thickness of patients with schizophrenia and patients with bipolar disorder to analyze the relationship of cortical mass with psychotic behavior. Patients were grouped based on diagnosis of schizophrenia (n=52), psychotic bipolar I disorder (n=49), non-psychotic bipolar I disorder (n=24), and healthy controls (n=40).  Clinical assessments scored both positive and negative symptoms using the Scale for the Assessment of Positive Symptoms (SAPS) and the Scale for the Assessment of Negative Symptoms (SANS), and magnetic resonance scans were used to measure thickness in 34 cortical regions.

Overall, cortical thickness did have a significant relationship with diagnosis (P=.001). Patients with schizophrenia had reduced cortical thickness in the frontal, parietal, and temporal cortices when compared with all other groups. An increase in thickness was found in the anterior cingulate cortex in all 3 disordered groups when compared to the healthy controls. Reduced mass at the middle temporal gyrus (r=-0.257; P =.001) and at the fusiform area (r=-0.255; P =.001) indicated significant links with predicting SAPS scores, and no areas were associated with predictions of SANS scores. Future studies need to evaluate the role of medication, gender, and age on cortical thickness.

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In conclusion, there was no similarity in cortical thinning between patients with schizophrenia and psychotic bipolar I disorder; in fact, the thickness in both bipolar arms was more similar to the healthy control arm.

This study was supported by the National Institute of Mental Health, the Taylor Family Institute, and the Center for Brain Research on Mood Disorders.


Godwin D, Alpert KI, Wang L, Mamah D. Regional cortical thinning in young adults with schizophrenia but not psychotic or non-psychotic bipolar I disorderInt J Bipolar Disord. 2018; 6:16. doi: 10.1186/s40345-018-0124-x