Neuromorphologische Korrelate dimensionaler schizotyper Persönlichkeitseigenschaften bei Gesunden

Schizotypy describes a multidimensional construct characterized by subclinical schizophrenia-like behavior and thinking. Schizotypy, also conceptualized as psychosis proneness, additionally shows overlapping in genetic predisposition and neuromorphometry with schizophrenia. Schizotypal personality traits occur in varying degrees in the population and form a continuum between low-schizotypy and high-schizotypy extending into a clinical range. While not pathological per se, they are a risk factor for the development of schizophrenia spectrum disorders. Schizotypy studies allow detecting differences within the continuum that may provide evidence for protective and compensatory factors buffering an underlying disposition. This study examined the extent to which schizotypal personality traits in healthy subjects correlate with structural features in neuromorphology. Therefore, schizotypal traits of 250 clinically healthy individuals were assessed using the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE), to examine the correlation of its subscales with brain structure using voxel-based morphometry (VBM), surface-based morphometry (SBM) and diffusion tensor imaging (DTI), respectively. We used a 3Tesla MRI to obtain imaging data. All three methods showed correlations between each subscale and brain structure. VBM analysis showed negative correlations in temporal and frontal areas, as well as results in the insula, cerebellum, and precuneus. Volume reductions in temporal areas were frequently found for clinically affected individuals, with volume reductions of the superior temporal gyrus in particular correlating with positive symptomatology. In the examined sample, the positive schizotypy dimension correlated with the inferior temporal gyrus but not with the superior temporal gyrus. Negative correlations in and around the precuneus also differ from other published results in healthy subjects. Furthermore, SBM analysis showed decreased gyrification in the frontal areas and increased gyrification in the insula. DTI analysis demonstrated associations of single dimensions with fiber quality presented in frontotemporal and fronto-subcortical fibertracts, as well as in structures of the limbic system. The results of the study thus demonstrate multifocal associations of different schizotypal personality traits with brain structure in healthy individuals, which are extending and, in some cases, contradicting previous findings. One explanation for this might be the use of different questionnaires. Hence, this study broadens the view on the schizotypal continuum and is important for understanding neuromorphological correlates of schizotypal traits in healthy individuals.