Schizotypal, schizoid and paranoid characteristics in the biological parents of social anhedonics.

Mounting evidence suggests that social anhedonia may be a marker of genetic liability for schizophrenia-spectrum pathology. To examine this hypothesis, we conducted a study of severity of schizotypal, schizoid and paranoid pathology (i.e., Cluster A personality disorders) in the biological parents of individuals with high levels of social anhedonia and healthy controls. Eighty-six individuals with social anhedonia, 89 healthy controls and their biological parents were recruited from a large community. Structured clinical interviews were conducted to obtain Cluster A diagnoses and symptom ratings for parents. The biological parents of socially anhedonic probands had elevated rates of Cluster A disorders (24%) compared with the parents of control probands (12%). Post hoc analyses revealed that these group differences were the result of elevated rates of diagnoses in the fathers of social anhedonic probands, but not the mothers. This finding was replicated when Cluster A symptoms were examined dimensionally. These findings are consistent with the hypothesis that social anhedonia is a promising indicator of the genetic vulnerability to schizophrenia-spectrum pathology. The unexpected findings of elevated pathology in fathers, but not mothers of socially anhedonic probands, require further exploration.