The intersection and developmental trajectory of morning cortisol and testosterone in autistic and neurotypical youth.

Background: Behavioral endocrinology examines associations between hormone expression, such as testosterone and cortisol, and behavior; both of which have been implicated in autism spectrum disorder (ASD). The overarching aim of the study was to examine the intersection of sex-based (Male, Female), hormonal (testosterone, cortisol), diagnostic (ASD, typically developing, (TD)) and developmental (age, puberty) patterns over four years of a longitudinal study in a well-characterized sample of youth (spanning 10 to 17 years).

Methods: In year 1 (Y1), participants included 140 autistic youth (36 females, 104 males) and 105 TD youth (46 females, 59 males.). For Y4, participants included 83 ASD and 77 TD youth. Immediate waking morning salivary samples were collected for hormone assay. Mixed effects and ordinary linear regression models were used, as well as mediation effects of hormones on behavior.

Results: For cortisol, there was a significant diagnosis by sex by age interaction (X² = 15.62, df = 3, p = 0.0014, S = 0.2446) showing that autistic females evidence higher morning cortisol that increased over developmental progression compared to TD females. Moreover, ASD males had stunted testosterone growth compared to TD males (Est = 0.1530, p = 0.0130). Regarding biobehavioral associations in year 1, diagnosis (X² = 80.72, df = 1, p < 0.0001, S = 0.5704) and cortisol (X² = 14.42, df = 3, p = 0.0024, S = 0.2159) were associated with social problems; however, there were no effects for testosterone on diagnosis or a mediation effect on social problems. There was a significant effect of diagnosis on CBCL Aggression score (X² = 34.39, df = 1, p < 0.0001, S = 0.3692) independent of hormonal measurements.

Limitations: Despite the large sample, it was not fully representative based on race, ethnicity or intellectual profile. Attrition of the sample is also acknowledged especially between portions of Y2 and Y3 due to the COVID-19 pandemic. Finally, only the immediate morning salivary samples were used due to lower and undetectable concentration levels of testosterone in younger and female children.

Conclusions: Collectively, these findings underscore the need to elucidate the biobehavioral patterns that emerge during the complex adolescent transition for autistic youth to determine how they impact clinical and long-term outcomes. The unique hormonal trajectories may be related to differences in advanced pubertal progression and affective states found in autistic females.