Sex Differences in the Developmental Trajectories of Autism Spectrum Disorder

Multiparametric Assays Capture Sex- and Environment-Dependent Modifiers of Behavioral Phenotypes in Autism Mouse Models

Background

Current phenotyping approaches for murine autism models often focus on one selected behavioral feature, making the translation onto a spectrum of autistic characteristics in humans challenging. Furthermore, sex and environmental factors are rarely considered. Here, we aimed to capture the full spectrum of behavioral manifestations in 3 autism mouse models to develop a "behavioral fingerprint" that takes environmental and sex influences under consideration.

Methods

To this end, we employed a wide range of classical standardized behavioral tests and 2 multiparametric behavioral assays-the Live Mouse Tracker and Motion Sequencing-on male and female Shank2, Tsc1, and Purkinje cell-specific Tsc1 mutant mice raised in standard or enriched environments. Our aim was to integrate our high dimensional data into one single platform to classify differences in all experimental groups along dimensions with maximum discriminative power.

Results

Multiparametric behavioral assays enabled a more accurate classification of experimental groups than classical tests, and dimensionality reduction analysis demonstrated significant additional gains in classification accuracy, highlighting the presence of sex, environmental, and genotype differences in our experimental groups.

Conclusions

Together, our results provide a complete phenotypic description of all tested groups, suggesting that multiparametric assays can capture the entire spectrum of the heterogeneous phenotype in autism mouse models.

Spontaneous instrumental approach-avoidance learning in social contexts in autism

BACKGROUND

Individuals with Autism Spectrum Condition (ASC) are characterized by atypicalities in social interactions, compared to Typically Developing individuals (TD). The social motivation theory posits that these difficulties stem from diminished anticipation, reception, and/or learning from social rewards. Although learning from socioemotional outcomes is core to the theory, studies to date have been sparse and inconsistent. This possibly arises from a combination of theoretical, methodological and sample-related issues. Here, we assessed participants' ability to develop a spontaneous preference for actions that lead to desirable socioemotional outcomes (approaching/avoiding of happy/angry individuals, respectively), in an ecologically valid social scenario. We expected that learning abilities would be impaired in ASC individuals, particularly in response to affiliative social feedback.

METHOD

We ran an online social reinforcement learning task, on two large online cohorts with (n = 274) and without (n = 290) ASC, matched for gender, age and education. Participants had to indicate where they would sit in a waiting room. Each seat was associated with different probabilities of approaching/avoiding emotional individuals. Importantly, the task was implicit, as participants were not instructed to learn, and emotional expressions were never mentioned. We applied both categorical analyses contrasting the ASC and TD groups and dimensional factor analysis on affective questionnaires.

RESULTS

Contrary to our hypothesis, participants showed spontaneous learning from socioemotional outcomes, regardless of their diagnostic group. Yet, when accounting for dimensional variations in autistic traits, as well as depression and anxiety, two main findings emerged among females who failed to develop explicit learning strategies: (1) autism severity in ASC correlated with reduced learning to approach happy individuals; (2) anxiety-depression severity across both ASC and TD participants correlated with reduced learning to approach/avoid happy/angry individuals, respectively.

CONCLUSIONS

Implicit spontaneous learning from socioemotional outcomes is not generally impaired in autism but may be specifically associated with autism severity in females with ASC, when they do not have an explicit strategy for adapting to their social environment. Clinical diagnosis and intervention ought to take into account individual differences in their full complexity, including the presence of co-morbid anxiety and depression, when dealing with social atypicalities in autism.

Healthy Prenatal Dietary Pattern and Offspring Autism

Importance

Prenatal diet may be causally related to autism; however, findings are inconsistent, with a limited body of research based on small sample sizes and retrospective study designs.

Objective

To investigate the associations of prenatal dietary patterns with autism diagnosis and autism-associated traits in 2 large prospective cohorts, the Norwegian Mother, Father, and Child Cohort Study (MoBa), and the Avon Longitudinal Study of Parents and Children (ALSPAC).

Design, Setting, and Participants

This cohort study used data from MoBa and ALSPAC birth cohort studies conducted across Norway and in the Southwest of England, respectively. Participants were people with singleton pregnancies with self-reported food frequency questionnaire responses. MoBa recruited between 2002 and 2008, and ALSPAC recruited between 1990 and 1992, and children were followed-up until age 8 years or older. Recruitment rates were 41% (95 200 of 277 702 eligible pregnancies) in MoBa and 72% (14 541 of 20 248 eligible pregnancies) in ALSPAC. Data analysis occurred February 1, 2022, to August 1, 2023.

Exposure

A healthy prenatal dietary pattern was derived using factor analysis and modeled as low, medium, and high adherence.

Main Outcomes and Measures

In MoBa, the offspring outcomes were autism diagnosis and elevated social communication questionnaire score at ages 3 years and 8 years, with further analysis of the social communication difficulties and restrictive and repetitive behaviors subdomains. In ALSPAC, offspring outcomes were elevated social communication difficulties checklist score at age 8 years. Odds ratios (ORs) were estimated using generalized nonlinear models.

Results

MoBa included 84 548 pregnancies (mean [SD] age, 30.2 [4.6] years; 43 277 [51.2%] male offspring) and ALSPAC had 11 760 pregnancies (mean [SD] age, 27.9 [4.7] years; 6034 [51.3%] male offspring). In the final adjusted models, high adherence to a healthy dietary pattern, compared with low adherence, was associated with reduced odds of autism diagnosis (OR, 0.78; 95% CI, 0.66-0.92) and social communication difficulties at age 3 years in MoBa (OR 0.76, 95% CI, 0.70-0.82) and age 8 years in ALSPAC (OR, 0.74; 95% CI, 0.55-0.98). There was no consistent evidence of association with the other outcomes.

Conclusions and Relevance

In this cohort study of mother-child dyads, adherence to a healthy prenatal dietary pattern was associated with a lower odds of autism diagnosis and social communication difficulties but not restrictive and repetitive behaviors.

Are the diagnostic rates of autistic females increasing? An examination of state-wide trends

BACKGROUND

Autism has been considered a 'male-dominant' condition. However, recent research suggests that autistic females are underdiagnosed, misdiagnosed, and later diagnosed. Females may also have different and more nuanced behavioral profiles. To examine diagnosis rates of females, we used 20 years of state-wide data to characterize historical trends in the diagnosis of autism in females to determine whether the proportion of females diagnosed with autism has changed over time.

METHODS

Data were drawn from 10,247 participants (males = 8,319, females = 1928) who received an autism diagnosis between 2000 and 2021 from state-wide autism centers associated with the University of North Carolina TEACCH Autism Program.

RESULTS

The rates of females diagnosed with autism increased at a greater rate compared with males. Age of diagnosis remained consistently higher for females. Late diagnosis (defined as 13+) increased over time across both males and females, however, was more commonly associated with females, particularly those with co-occurring intellectual disability.

CONCLUSIONS

Our results indicate that the proportion of females diagnosed with autism has increased steadily over a 20-year period, which likely reflects greater societal knowledge of how autism may manifest differentially in females.

Sex Differences in Autistic Youth Born Extremely Preterm

PURPOSE

To evaluate sex differences in autistic traits in youth born extremely preterm (EP; 23-27 weeks) who were later diagnosed with autism spectrum disorder (ASD) at 10-years.

METHOD

A longitudinal cohort design from the Extremely Low Gestational Age Newborn Study (ELGAN) followed N = 857 EP infants from birth through 10-years. EP infants later diagnosed with ASD (N = 61, 20 females) participated in the study. Group differences were evaluated via inferential and Bayesian statistics (values > 1 suggest evidence for alternate hypothesis) on ASD screeners (M-CHAT at 2-years, SCQ and SRS-2 at 10-years), and gold-standard diagnostic measures (ADOS-2, ADI-R) at 10-years.

RESULTS

Males scored significantly higher than females on measures of Social Affect from the ADOS-2, t(34.27)=-2.20, BF10 = 2.33, and measures of Repetitive and Restricted Behaviors from the ADI-R, t(40.52)=-2.85, BF10 = 5.26. Bayesian estimates suggested marginal evidence for sex differences in Nonverbal Communication, t(30.66)=-1.81, BF10 = 1.25, and Verbal Communication, t(24.64)=-1.89, BF10 = 1.39, from the ADI-R, wherein males scored higher than females. No statistically significant sex differences were identified on any of the ASD screeners at 2 (M-CHAT) or 10 years (SCQ). No significant sex differences were observed on any subscales of the SRS at 10 years.

CONCLUSIONS

EP autistic males present with more autistic traits than EP autistic females on gold-standard diagnostic measures of autism at 10-years of age, despite not presenting with higher autistic traits on screeners at either age. These results align with sex differences observed in full-term, autistic youth. These results suggest ASD screeners may under identify autism in EP youth, particularly females.

Uncovering employment outcomes for autistic university graduates in the United Kingdom: An analysis of population data

LAY ABSTRACT

International research suggests that more autistic people are entering higher education. Currently, very little is known about this group in the United Kingdom, for example, we have little information about how many autistic people enrol at UK-based higher education institutions, their backgrounds, the academic programmes they study and what they do once they have graduated. Our study tries to explore these issues by comparing outcomes between autistic students, other disabled students and non-disabled students. We use population data collected by the Higher Education Statistical Agency in the United Kingdom, which included 1,326,416 graduates across the years 2012-2018. Our findings indicate that the degree subjects studied at university by autistic students are more diverse than often people think. We also found that graduates go on to work in a range of employment sectors following graduation but often experience worse outcomes in terms of access to full-time work and worse pay. We argue that universities and colleges must focus greater attention on developing better employment transition support for autistic students and graduates.

A developmental framework for understanding the influence of sex and gender on health: Pediatric pain as an exemplar

Sex differences are a robust finding in many areas of adult health, including cardiovascular disease, psychiatric disorders, and chronic pain. However, many sex differences are not consistently observed until after the onset of puberty. This has led to the hypothesis that hormones are primary contributors to sex differences in health outcomes, largely ignoring the relative contributions of early developmental influences, emerging psychosocial factors, gender, and the interaction between these variables. In this paper, we argue that a comprehensive understanding of sex and gender contributions to health outcomes should start as early as conception and take an iterative biopsychosocial-developmental perspective that considers intersecting social positions. We present a conceptual framework, informed by a review of the literature in basic, clinical, and social science that captures how critical developmental stages for both sex and gender can affect children's health and longer-term outcomes. The literature on pediatric chronic pain is used as a worked example of how the framework can be applied to understanding different chronic conditions.

Improving autism identification and support for individuals assigned female at birth: clinical suggestions and research priorities

Emerging evidence suggests that the higher prevalence of autism in individuals who are assigned male than assigned female at birth results from both biological factors and identification biases. Autistic individuals who are assigned female at birth (AFAB) and those who are gender diverse experience health disparities and clinical inequity, including late or missed diagnosis and inadequate support. In this Viewpoint, an international panel of clinicians, scientists, and community members with lived experiences of autism reviewed the challenges in identifying autism in individuals who are AFAB and proposed clinical and research directions to promote the health, development, and wellbeing of autistic AFAB individuals. The recognition challenges stem from the interplay between cognitive differences and nuanced or different presentations of autism in some AFAB individuals; expectancy, gender-related, and autism-related biases held by clinicians; and social determinants. We recommend that professional development for clinicians be supported by health-care systems, professional societies, and governing bodies to improve equitable access to assessment and earlier identification of autism in AFAB individuals. Autistic AFAB individuals should receive tailored support in education, identity development, health care, and social and professional sense of belonging.

Sex/Gender Differences in the Language Profiles of Italian Children with Autism Spectrum Disorder: A Retrospective Study

Sex/gender (S/G) differences in ASD language profiles have been poorly investigated. The present study aims to explore whether male (M) and female (F) children with ASD and with normal non-verbal cognitive abilities differ in their linguistic profiles. A sample of 76 Italian children with ASD (range: 4.9-8 years), including 50 Ms and 26 Fs, was retrospectively recruited. Language profiles were analyzed using standardized tests for the evaluation of receptive and expressive vocabulary as well as grammar. Grammatical comprehension was the most impaired domain compared to the other language measures in both M and F children. Comparing language profiles between S/G, Fs showed significantly better scores than Ms in grammatical production (p = 0.002), and Ms showed better active negative sentence comprehension (p = 0.035). Moreover, comparing the language profiles between Ms and Fs with a receptive disorder, Fs had significantly worse grammatical comprehension and better grammatical production than Ms. Even among children without a receptive disorder, Fs had significantly higher grammatical production scores. The S/G differences in language profile, particularly better expressive language in Fs than Ms, can partially contribute to the delayed ASD diagnosis or underdiagnosis of Fs without intellectual disability. Finally, the results document the importance of accurately investigating both expressive and receptive abilities in children with ASD.