# Common Relationship Between Causality Orientation and the Prefrontal Region in Psychiatric Disorders as Revealed by Diffusional Kurtosis Imaging

## TL;DR

This study finds a link between motivation and brain structure in the prefrontal region across several psychiatric disorders.

## Contribution

It identifies a transdiagnostic relationship between intrinsic motivation and microstructural brain features using diffusional kurtosis imaging.

## Key findings

- Psychiatric patients showed positive correlations between autonomy orientation scores and mean kurtosis in prefrontal regions.
- The link was consistent across schizophrenia, MDD, and BD, especially in female patients.
- This suggests a potential new biomarker for psychiatric disorders.

## Abstract

Background

Motivation dysregulation is common in several psychiatric disorders. However, little is known about the relationships between motivation and the regional brain areas involved. We evaluated the relationships between brain microstructural features and causality orientation in patients with schizophrenia, major depressive disorder (MDD), and bipolar disorder (BD) using diffusional kurtosis imaging (DKI) techniques.

Methods

Forty patients with MDD, 36 with BD, and 30 with schizophrenia underwent DKI and assessment using the General Causality Orientation Scale (GCOS). We analyzed the DKI index and the GCOS subscales.

Results

The psychiatric patients showed significant positive correlations between the GCOS-autonomy orientation score and the mean kurtosis (MK) values in the prefrontal regions, orbitofrontal regions, and posterior cingulate cortex. When the analyses were performed separately by disease and gender, a positive correlation was found between the GCOS-autonomy orientation score and the MK values in the left prefrontal regions transdiagnostically, especially among female patients with MDD, BD, and schizophrenia.

Conclusions

A similar association between intrinsic motivation and MK value in the left prefrontal cortex was suggested in patients with schizophrenia, MDD, and BD. The commonality of this association among these disorders might lead to the discovery of a new biomarker for psychiatric clinical research.