Background: Concerns have been raised that scores on standard measures of autism spectrum disorder (ASD) symptoms may differ as a function of sex. However, these findings are hindered by small female samples studied thus far. The current study evaluated if, after accounting for age, IQ, and language level, sex affects ASD severity estimates from diagnostic measures among children with ASD. Methods: Data were obtained from eight sources comprising 27 sites. Linear mixed-effects models, including a random effect for site, were fit for 10 outcomes (Autism Diagnostic Observation Schedule [ADOS] domain-level calibrated severity scores, Autism Diagnostic Interview-Revised [ADI-R] raw scores by age-based algorithm, and raw scores from the two indices on the Social Responsiveness Scale [SRS]). Sex was added to the models after controlling for age, NVIQ, and an indicator for language level. Results: Sex significantly improved model fit for half of the outcomes, but least square mean differences were generally negligible (effect sizes [ES] < 0.20), increasing to small to moderate in adolescence (ES < 0.40). Boys received more severe RRB scores than girls on both the ADOS and ADI-R (age 4 + algorithm), and girls received more severe scores than boys on both SRS indices, which emerged in adolescence. Conclusions: This study combined several available databases to create the largest sample of girls with ASD diagnoses. We found minimal differences due to sex beyond other known influences on ASD severity indicators. This may suggest that, among children who ultimately receive a clinical ASD diagnosis, severity estimates do not systematically differ to such an extent that sex-specific scoring procedures would be necessary. However, given the limitations inherent in clinically ascertained samples, future research must address questions about systematic sex differences among children or adults who do not receive clinical diagnoses of ASD. Moreover, while the current study helps resolve questions about widely used diagnostic instruments, we could not address sex differences in phenotypic aspects outside of these scores.

Cardiac activity, such as heart rate and heart rate variability, is linked to a wide range of psychological functions. This study shows that there is an association between heart rate and heart rate variability and language skills in young children with autism spectrum disorder (ASD). These results may help us understand what underlies individual differences in developmental abilities in young children with ASD.

Anecdotal reports and a small number of research studies suggest possible behavioral improvements in children with autism spectrum disorders (ASD) during a fever. However, previous studies rely largely on retrospective reports of this phenomenon. Establishing a robust association between fever and reduction of ASD‐related symptoms would promote opportunities for the development of innovative therapeutic interventions for children with ASD. In the current study, prospective data were collected from 141 children with ASD and 103 typically developing (TD) controls using parent responses to an 11‐item behavioral survey. Behaviors when no illness was present, during a fever, the week after a fever, and during non‐febrile illnesses for TD and ASD children were compared. Profiles of cases in which caregivers reported consistent behavioral improvements during fever are described. Data indicated worsening social, emotional/behavioral, and somatic symptoms during a fever regardless of diagnosis, with children with ASD demonstrating greater worsening of behaviors during a fever than TD children. Only three out of 141 children with ASD demonstrated consistent behavioral improvements during a fever; these children had a range of cognitive and adaptive skills. Children with ASD had stronger negative responses to fever than TD children. These findings contradict previous literature suggesting behavioral improvements for children with ASD. While improvements may occur for some children, it does not appear to be a common phenomenon. Additional research is needed to elucidate the nature of behavioral improvements in the subset of children with ASD who may respond positively to fever.

Purpose: Daily mood can be influenced by a range of experiences. Identifying everyday life experiences that make autistic adults happy and unhappy holds potential to foster positive mood and tackle mental health problems amongst this group. Methods: A total of 293 autistic adults between the ages of 18 to 35 years old (mean age of 26.51 years old ( SD = 4.62); 43.3% female gender, 4.8% nonbinary) provided open-text responses regarding everyday sources of happiness and unhappiness. Using an iterative process of inductive coding, 14 happy themes and 22 unhappy themes of mood-changing life experiences were identified based on self-report qualitative data. Results: Common themes across the happy and unhappy domain involved social partners, social interactions, and engagement in recreational and employment activities, with additional distinct themes specific to happy or unhappy mood. Top themes identified in the happy domain emphasizes encouraging quality relationships and positive interactions with others and cultivating supportive work/societal environments to build a sense of achievement and value. Meanwhile, emotional tolls accompanied negative relationships and interactions, underscoring the necessity to provide autistic adults with conflict resolution and coping skills to increase feelings of happiness. Conclusion: Overall, the wide range of sources of happy and unhappy everyday experiences highlights the importance of considering personal preferences in engagement with others and activities in treatment.