Oxytocin’s Role As a Biomarker of Early Social Cognitive Ability in Preschoolers with and without ASD

Background: Individuals with autism spectrum disorder (ASD) show pervasive deficits in social cognition (White et al., 2007). The hormone oxytocin (OT) has been implicated in the social difficulties individuals with ASD face (Carter, 2007) which has led to the use of OT as a pharmacological intervention. However, studies to date show mixed results, which has left some questioning the efficacy and importance of OT (Young, 2015). A better understanding of basal OT concentration levels and its relationship to early social cognitive abilities in both typically developing children and those with ASD could help delineate the role of OT as a potential biomarker.

Objectives: Explore the relationship between OT salivary concentration levels between preschoolers with ASD and typically developing (TD) peers and social cognitive ability.

Methods: Nineteen children with ASD (age = 4.27; 75% male; Mullen VR = 31.12 (9.33)) and 21 TD children (age = 4.47; 61% male; Mullen VR = 47.57 (14.39)) participated in the current study. During an in-person visit, salivary samples were collected from participants at the start of the visit and used for OT extraction (Salimetrics Salivabio children’s swab; Arbor Assays DetectX Enzyme Immunoassay Kit). Then, child participants completed measures of pretend play (Affect in Play Scale – Preschool version), social cognition tasks measuring joint attention, empathy, and cooperation, emotional understanding, and a parent-child interaction task.

Results: TD and ASD preschoolers did not differ in salivary OT concentration levels (F = 2.55; p = 0.16) at baseline. Across the sample, parent involvement in play correlated with child OT levels (r = 0.38, p = 0.05). Within the TD group, OT levels significantly related to interpersonal aggression in play (r = -0.47; p = 0.04), ability to recognize negative emotions (r = 0.51; p = 0.03), and joint attention ability (r = 0.59; p = 0.01). In the ASD group, interpersonal aggression (r = 0.79; p = 0.01), transformations (r = 0.79, p = 0.01) and divergent storylines (r = 0.77, p = 0.01) in pretend play correlated with baseline OT levels as did emotional recognition (r = 0.78; p = 0.07) and the ability to express empathy (r = 0.67, p = 0.05).

Conclusions: The relationship between parental involvement and OT expression suggests that more parent involvement may relate to higher child OT concentration levels irregardless of disorder category, perhaps suggesting that increasing parental involvement may then impact child OT levels. Findings also indicate that OT may have a unique relationship with specific domains of social cognitive ability, such as pretend play, emotional understanding, joint attention and empathy, in individuals with ASD as compared to TD children. This provides support for the notion of OT as a biomarker, which may have farther reaching effects that extend to individual differences in social functioning across disorder category, including the severe social impairment evidenced in ASD. These findings may allow for better understanding of how OT can be used as a biomarker for earlier identification of social cognitive deficits and potentially as a predictor of treatment outcomes.