Association between brain structure and psychometric schizotypy in healthy individuals

Schizophrenia is associated with replicable grey matter volume reductions in fronto-temporo-limbic and subcortical regions. Psychometric schizotypy refers to a set of behavioural traits and cognitions thought to represent the subclinical manifestation of schizophrenia in the general population. While there is evidence of a continuum between schizophrenia and schizotypy at phenotypic, genetic and cognitive levels, no previous study has observed grey matter volume reductions associated with increased psychometric schizotypy levels in healthy individuals. Such evidence would provide further support for a relationship between non-clinical schizophrenia-like traits in the general population and the full-blown clinical condition of schizophrenia.

We used magnetic resonance imaging to investigate the relationship between psychometric schizotypy and brain structure in 55 clinically unaffected and unmedicated volunteers. We performed a voxel-based morphometry analysis of grey matter volume data obtained at 1.5 Tesla.

Covarying for age and gender, higher scores of self-report positive schizotypy were significantly associated with reduced grey matter volume in medial prefrontal, orbitofrontal, and temporal cortical regions.

These findings show that psychometric schizotypy in healthy individuals is associated with volume reductions in cortical areas known to be altered in schizophrenia, thereby providing neurobiological evidence of a continuum between schizotypy and schizophrenia.