• schizophrenia;
  • phenotype;
  • magnetic resonance imaging;
  • brain

Objective: Previous studies have suggested that several code types of the Minnesota Multiphasic Personality Inventory (MMPI) are useful markers for identifying schizophrenia. We hypothesized that schizotypal disorder (STD) patients with such schizophrenia-related code types have the morphological brain abnormalities associated with schizophrenia.

Method: Voxel-based morphometric analysis with statistical parametric mapping (SPM) 99 software was used to investigate the differences in brain morphology between 14 STD patients with the schizophrenia-related code types of the MMPI and 28 normal individuals.

Results: The STD patients showed significantly decreased gray matter volume in the insular regions bilaterally and in the left entorhinal cortex, compared with the controls.

Conclusion: Our findings suggest that STD patients with the schizophrenia-related code types have volume reductions in these regions as an endophenotype that overlaps with schizophrenia.