Oxytocin Plasma Concentrations in Male Children and Adolescents with Autism Spectrum Disorder: Relationship with Aggression and Empathy Skills

Abstract

Objective: Findings from various studies in animal models and humans have demonstrated a clear role of neuropeptide oxytocin (OT) on complex social behaviors. Oxytocin is known to mediate social interactions, and as a result, it has been investigated in a number of psychiatric disorders. This study aims to explore the link between aggression and empathy and OT levels in children with Autism Spectrum Disorder (ASD). Methods: Thirty-two male ASD patients, ranging in age from 8 to 15 years, and 30 healthy age – and sex-matched controls were included in this study. All patients were assessed with the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime version-Turkish version (K-SADS-PL), the Reading the Mind in the Eyes Test (RMET) and Childhood Autism Rating Scale (CARS). The patients’ and the healthy controls’ parents filled out the Abnormal/Aberrant Behavior Checklist (ABC), Children’s Aggression Scale-Parent Version (CAS-P) and Griffith Empathy Measure-Parent Evaluation Form (GEM-PEF). Serum OT levels of the groups were compared. Results: Higher serum OT levels were observed in ASD cases compared to the healthy controls. There was no significant difference between the groups’ OT levels (p=0.155). When the RMET and the GEM-PEF scores were compared among the groups both; RMET scores and GEM- PEF scores of children in the ASD group were statistically significantly lower (p <0.001) than the control group. No significant difference in CAS-P mean scores was identified between the groups. In both groups, there was no correlation between aggression and empathy levels and serum OT levels. Conclusion: In our study, serum OT levels and aggressive behaviors did not significantly differ between the groups. We detected statistically lower empathy scores in patients with ASD. However, we did not find a relationship between serum OT levels and aggressive behaviors and empathy skills. In order to determine the relationship between serum OT level and aggressive behaviors and empathy skills, and to generalize the findings, population-based, series of studies with larger samples are needed.