Salivary Oxytocin Levels Lower in Children with ASD, Correlate with Self-Esteem and Social Support

The autism spectrum disorder (ASD) is characterized by significant social and emotional difficulties, with growing evidence pointing to dysregulation in the oxytocinergic and immune systems. While oxytocin, a crucial neuropeptide, is known for its role in social behavior, the precise associations between endogenous oxytocin levels, inflammatory markers, and internal psychological constructs like self-esteem and social support in ASD remain unclear. Current understanding suggests that atypical oxytocinergic functioning contributes to ASD pathophysiology, but the direct links to specific socio-emotional outcomes and the interplay with inflammatory pathways like IL-1β, IL-6, and IL-8 require further elucidation.

This study included 26 children and adolescents with ASD and 23 typically developing (TD) controls to investigate the relationship between salivary oxytocin (OT) levels, inflammatory markers, self-esteem, and perceived social support. Salivary oxytocin and inflammatory cytokine levels (IL-1β, IL-6, IL-8) were quantified using enzyme-linked immunosorbent assays and multiplex immunoassays. The primary objective was to examine how these biological factors correlate with psychological measures of socio-emotional functioning across both groups, adjusting for age. Participants completed questionnaires assessing self-esteem and perceived social support.

Salivary oxytocin levels were significantly lower in the ASD group compared to the TD group after adjusting for age, indicating a potential biological marker for socio-emotional challenges in ASD. In contrast, no significant group differences were observed in the measured inflammatory markers, including IL-1β, IL-6, or IL-8, suggesting these specific cytokines may not be primary drivers of the observed socio-emotional differences in this cohort. Importantly, across all 49 participants, including those with ASD, higher salivary oxytocin levels were consistently associated with greater self-esteem and perceived social support. This association highlights oxytocin's broad role in psychological well-being, irrespective of diagnostic status.

Participants with higher OT levels were associated with greater self-esteem and perceived social support, underscoring oxytocin's role in positive socio-emotional outcomes. Among the inflammatory markers, none of the cytokines (IL-1β, IL-6, or IL-8) showed significant associations with the psychological measures, including AQ-J total scores, further differentiating the roles of oxytocin and inflammation in socio-emotional functioning.