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 ScaleParent 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 GEMPEF 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.

Key words: Autism, Neuropeptides, Oxytocin, Empathy, Aggression