Sex-specific associations between plasma oxytocin levels and schizotypal personality features in healthy individuals

Objectives: Oxytocin (OT) has been shown to play a crucial role in the biology of social interaction. Sex differences associated with this neuropeptide system have been reported. OT may serves as an indicator of interpersonal stress, especially in women. The aim of this study was to investigate the sex-specific associations between plasma OT levels and schizotypal personality features, especially in interpersonal dimension, in healthy individuals. Methods: Ninety six healthy participants, including 41 males and 55 females, were recruited. Fasting blood samples were analyzed by enzyme immunoassay of OT. The Schizotypal Personality Questionnaire (SPQ) was administered. Mann-Whitney U test was used to test the difference between male and female. Spearman's ρ; correlation analysis (two-tailed) was carried out to examine the association between OT level and SPQ score. Results: The results showed that OT level was significantly positively correlated with total score and interpersonal dysfunction dimensional scores of the SPQ only in females. Conclusions: Although the causal relationship remains unclear, our findings provide further evidence to support the sexual dimorphic role of OT in interpersonal biology. Moreover, the effect of sex difference also is taken into consideration.