Fronto-Thalamic Structural Connectivity Associated With Schizotypy, a Psychosis Risk Phenotype, in Nonclinical...

Area of Science:

• Neuroimaging
• Psychiatry
• Genetics

Background:

• Schizotypy is a risk phenotype for psychosis spectrum disorders.
• A biological continuum may underlie schizotypy across health and disease.
• Brain structural associations in schizophrenia spectrum disorder networks are unclear in schizotypy.

Purpose of the Study:

• To investigate brain structural associations in nonclinical subjects with schizotypal traits.
• To explore the biological continuum of schizotypy across health and disease.
• To examine fronto-thalamo-striatal and default mode network alterations in schizotypy.

Main Methods:

• Analysis of a large multi-center cohort (n=673) of nonclinical subjects.
• Phenotyping schizotypal traits using the Schizotypal Personality Questionnaire-Brief version.
• Tract-based spatial statistics of diffusion tensor imaging, voxel-based morphometry, and gyrification analysis.

Main Results:

• Significant associations between schizotypy and major fiber tract fractional anisotropy.
• Positive schizotypy correlated negatively with left anterior thalamic radiation, uncinate fasciculus, and cingulum.
• Negative schizotypy correlated positively with left anterior thalamic radiation, cingulum, and anterior corpus callosum; disorganized schizotypy correlated negatively with right cingulum and longitudinal fasciculi.
• VBM showed negative gray matter correlation with negative schizotypy in the left cerebellum.
• Gyrification in the inferior parietal cortex positively correlated with negative schizotypy.

Conclusions:

• Findings support a neural network conceptualization of schizotypy.
• Schizotypy is associated with fronto-subcortical and frontotemporal systems.
• These brain systems serve as structural substrates for this psychosis risk phenotype.