Genetically based correlates of serum oxytocin and testosterone in autism and schizotypy

The hormones oxytocin and testosterone have been implicated in autism spectrum and schizophreniaspectrum cognition and disorders, but their roles in mediating these psychological phenotypes remain largely unknown. We genotyped a large set of healthy individuals for loci that represent established genetic indicators of serum testosterone and oxytocin levels, and tested for associations of these genetic indices of hormone levels with self-report measures of autistic and schizotypal cognition. A low genetic index of testosterone, a high genetic index of oxytocin, and/or a low ratio of testosterone to oxytocin indices were positively correlated with high imagination (by the Autism Quotient) and high positive and total schizotypy (by the Schizotypal Personality Questionnaire). The genetic indices for oxytocin, and testosterone relative to oxytocin, also showed significant correlations with a metric of positive schizotypy relative to autism, implicating higher oxytocin and lower testosterone in increased positively-schizotypal traits combined with decreased autism-associated traits. These results link genetic indicators of serum hormone levels with measures of schizotypy and autism among healthy individuals. ! 2015 Elsevier Ltd. All rights reserved.