Oxytocin but Not Testosterone Modulates Behavioral Patterns in Autism Spectrum Disorders

Autism spectrum disorder (ASD) is a neurodevelopmental disorder of unknown etiology. Social deficits represent one of the core symptoms of the diagnosis. The aim was to reveal possible correlations among peripheral levels of oxytocin and testosterone with behavioral and symptom characteristics in patients with ASD. 8 children with ASD were recruited and underwent psychological profiling. Blood oxytocin and testosterone levels were analyzed using ELISA method. Oxytocin levels positively correlated with Adaptation to change category of CARS-2 (P = 0.008, R = 0.848) and Vineland-II maladaptive behavior scores (P = 0.004, R = 0.884). No significant correlations were found among testosterone levels and behavioral parameters. Higher oxytocin levels were connected with more severe adaptive behavior in ASD patients. Increased oxytocin levels in children with more severe phenotype could be a result of compensatory mechanism of impaired oxytocin signaling. Oxytocin seems to employ distinct mechanisms in regulating social behavior in autism and healthy population

Testosterone and Androgen Receptor Sensitivity in Relation to Hyperactivity Symptoms in Boys with Autism Spectrum Disorders.

INTRODUCTION:Autism spectrum disorders (ASD) and hyperactivity symptoms exhibit an incidence that is male-biased. Thus androgen activity can be considered a plausible biological risk factor for these disorders. However, there is insufficient information about the association between increased androgen activity and hyperactivity symptoms in children with ASD. METHODS:In the present study, the relationship between parameters of androgenicity (plasmatic testosterone levels and androgen receptor sensitivity) and hyperactivity in 60 boys (age 3-15) with ASD is investigated. Given well documented differences in parent and trained examiners ratings of symptom severity, we employed a standardized parent`s questionnaire (Nisonger Child Behavior Rating Form) as well as a direct examiner`s rating (Autism diagnostic observation schedule) for assessment of hyperactivity symptoms. RESULTS:Although it was found there was no significant association between actual plasmatic testosterone levels and hyperactivity symptoms, the number of CAG triplets was significantly negatively correlated with hyperactivity symptoms (R2 = 0.118, p = 0.007) in the sample, indicating increased androgen receptor sensitivity in association with hyperactivity symptoms. Direct trained examiner´s assessment appeared to be a relevant method for evaluating of behavioral problems in the investigation of biological underpinnings of these problems in our study. CONCLUSIONS:A potential ASD subtype characterized by increased rates of hyperactivity symptoms might have distinct etiopathogenesis and require a specific behavioral and pharmacological approach. We propose an increase of androgen receptor sensitivity as a biomarker for a specific ASD subtype accompanied with hyperactivity symptoms. Findings are discussed in terms of their implications for practice and future research

Correlations between CAG (n) in gene encoding AR and hyperactivity symptoms in the sample.

<p>(A) CAG (n) was not associated with total score on the hyperactivity subscale of NCBRF (R² = 0.007, p = ns) (B) CAG (n) was significantly negatively correlated with the overactivity score on ADOS-2 (R² = 0.118, p = 0.007).</p

Correlation matrix table including Pearson correlation coefficient (R) and sample size <i>n</i> with the variables analyzed in groups of boys with ASD.

<p>Correlation matrix table including Pearson correlation coefficient (R) and sample size <i>n</i> with the variables analyzed in groups of boys with ASD.</p