Current Auditory Hallucinations Are Not Associated With Specific White Matter Diffusion Alterations in Schizophrenia.

Area of Science:

• Neuroimaging
• Schizophrenia Spectrum Disorders
• White Matter Microstructure

Background:

• Auditory hallucinations (AH) in schizophrenia spectrum disorders (SCZ) are often linked to altered white matter in language and auditory processing circuitry (LAPC).
• The specificity of these white matter alterations to LAPC in relation to AH remains unclear.

Purpose of the Study:

• To investigate the relationship between AH and white matter microstructure using diffusion tensor imaging (DTI) in patients with SCZ.
• To determine if DTI alterations are specific to the LAPC in patients experiencing AH.

Main Methods:

• Included patients with SCZ with (AH+) and without (AH-) current AH, and healthy controls.
• Extracted DTI metrics (FA, MD, RD, AD) from 39 fiber tracts.
• Used principal component analysis (PCA) and regression models to compare DTI metrics and PCA factors between groups and assess clinical associations.

Main Results:

• Patients without current AH (AH-) showed widespread differences in mean diffusivity (MD) and radial diffusivity (RD) compared to controls.
• Only limited DTI differences were found between patients with AH (AH+) and controls.
• PCA factors differed significantly from controls for AH- patients, but not for AH+ patients.

Conclusions:

• Contrary to prior research, DTI metrics alterations were more prominent in SCZ patients without current AH, suggesting widespread neuroanatomical distribution.
• These findings challenge the hypothesis that altered DTI metrics within the LAPC are a specific neural correlate of AH in SCZ.