Autistic traits below the clinical threshold: re-examining the broader autism phenotype in the 21st century

Assessing Autistic Traits, Hikikomori Tendencies, Pathological Videogaming, and Eating Disorders in University Students: Are Pathological Videogaming and Eating Disorders Gender-Specific Manifestations of the Autism Spectrum?

In the previous literature, specific attention has been paid to investigate autism spectrum symptoms and traits in university students. In this framework, we aimed to evaluate the presence and correlates of autistic traits, hikikomori tendencies, altered eating behaviors, and pathological videogaming in a sample of Italian university students enrolled in bachelor's degree courses. A total of 1192 students were recruited via an online survey and assessed with the Hikikomori Questionnaire-25, the Adult Autism Subthreshold Spectrum Questionnaire, the Eating Attitude test-26, and the Assessment of Internet and Computer Game Addiction. Our results highlighted significant differences in the prevalence of autistic traits, social withdrawal tendencies, altered eating habits, and pathological videogame use in university students based on gender, age, parents' level of instruction, and field of study. A significant effect of the presence of autistic traits and gender on the scores obtained with the other questionnaires was reported. Our results not only support the role of autistic traits as a vulnerability factor for the development of a set of psychopathological conditions but also suggest that gender could modulate this vulnerability, supporting the hypothesis of gender-specific phenotypes in the autism spectrum.

Platelet Levels of Brain-Derived Neurotrophic Factor in Adults with Autism Spectrum Disorder: Is There a Specific Association with Autism Spectrum Psychopathology?

To date, although several studies have investigated the circulating levels of brain-derived neurotrophic factor (BDNF) in children with autism spectrum disorder (ASD), only a few authors have addressed their evaluation in adults. Furthermore, an important limitation of these studies lies in the fact that circulating BDNF is stored in platelets and released into the circulation when needed. To the best of our knowledge, a very limited number of studies have related peripheral BDNF values to platelet counts, and yet no study has evaluated intra-platelet BDNF levels in adults with ASD. In this framework, the aim of the present work is to pave the way in this field and evaluate platelet BNDF levels in adult ASD patients, as well as their correlation with autistic symptoms and related psychopathological dimensions. We recruited 22 ASD and 22 healthy controls, evaluated with the Adult autism subthreshold spectrum (AdAS Spectrum), the Social Anxiety Spectrum-self report (SHY-SR), the Trauma and loss spectrum-self report (TALS-SR), the Work and Social Adjustment Scale (WSAS), and the Mood Spectrum-self report for suicidality. Intra-platelet BDNF levels were also assessed. The results highlighted lower BDNF levels in the ASD group; moreover, AdAS Spectrum and WSAS total score as well as AdAS Spectrum Restricted interest and rumination, WSAS Private leisure activities, TALS-SR Arousal, and SHY-SR Childhood domains were significant negative predictors of platelet BDNF levels.

Visuo-motor updating in individuals with heightened autistic traits

Autism spectrum disorder (ASD) presents a range of challenges, including heightened sensory sensitivities. Here, we examine the idea that sensory overload in ASD may be linked to issues with efference copy mechanisms, which predict the sensory outcomes of self-generated actions, such as eye movements. Efference copies play a vital role in maintaining visual and motor stability. Disrupted efference copies hinder precise predictions, leading to increased reliance on actual feedback and potential distortions in perceptions across eye movements. In our first experiment, we tested how well healthy individuals with varying levels of autistic traits updated their mental map after making eye movements. We found that those with more autistic traits had difficulty using information from their eye movements to update the spatial representation of their mental map, resulting in significant errors in object localization. In the second experiment, we looked at how participants perceived an object displacement after making eye movements. Using a trans-saccadic spatial updating task, we found that those with higher autism scores exhibited a greater bias, indicating under-compensation of eye movements and a failure to maintain spatial stability during saccades. Overall, our study underscores efference copy's vital role in visuo-motor stability, aligning with Bayesian theories of autism, potentially informing interventions for improved action-perception integration in autism.

Case report: hikikomori syndrome in Italy and its link with autistic traits and internet gaming disorder

During the last few decades, a growing field of literature is focusing on hikikomori, a phenomenon described as a form of pathological social withdrawal or social isolation that lasts for more than 6 months leading to significant functional impairment and/or distress. Despite initially considered a culture-bound syndrome, hikikomori syndrome later gained a wider recognition in different countries, ranging from an attempt to take refuge in an idealistic world, when society success' standards are not reached, to a maladaptive coping strategy complicating several psychiatric illnesses such as anxiety disorders, major depression, internet addiction, internet gaming disorder (IGD) and autism spectrum disorder (ASD). In this framework, difficulties in social interaction, in problem solving strategies and socio-emotional reciprocity, may lead to social withdrawal and hikikomori-like behaviors. In this work, we described two cases of patients where the presence of underlying autism spectrum may have represented a sign of vulnerability towards the development of a possible full-blown case of hikikomori with IGD.

A Systematic Review on Autism and Hyperserotonemia: State-of-the-Art, Limitations, and Future Directions

Hyperserotonemia is one of the most studied endophenotypes in autism spectrum disorder (ASD), but there are still no unequivocal results about its causes or biological and behavioral outcomes. This systematic review summarizes the studies investigating the relationship between blood serotonin (5-HT) levels and ASD, comparing diagnostic tools, analytical methods, and clinical outcomes. A literature search on peripheral 5-HT levels and ASD was conducted. In total, 1104 publications were screened, of which 113 entered the present systematic review. Of these, 59 articles reported hyperserotonemia in subjects with ASD, and 26 presented correlations between 5-HT levels and ASD-core clinical outcomes. The 5-HT levels are increased in about half, and correlations between hyperserotonemia and clinical outcomes are detected in a quarter of the studies. The present research highlights a large amount of heterogeneity in this field, ranging from the characterization of ASD and control groups to diagnostic and clinical assessments, from blood sampling procedures to analytical methods, allowing us to delineate critical topics for future studies.

Infants' reorienting efficiency depends on parental autistic traits and predicts future socio-communicative behaviors

Attentional reorienting is dysfunctional not only in children with autism spectrum disorder (ASD), but also in infants who will develop ASD, thus constituting a potential causal factor of future social interaction and communication abilities. Following the research domain criteria framework, we hypothesized that the presence of subclinical autistic traits in parents should lead to atypical infants' attentional reorienting, which in turn should impact on their future socio-communication behavior in toddlerhood. During an attentional cueing task, we measured the saccadic latencies in a large sample (total enrolled n = 89; final sample n = 71) of 8-month-old infants from the general population as a proxy for their stimulus-driven attention. Infants were grouped in a high parental traits (HPT; n = 23) or in a low parental traits (LPT; n = 48) group, according to the degree of autistic traits self-reported by their parents. Infants (n = 33) were then longitudinally followed to test their socio-communicative behaviors at 21 months. Results show a sluggish reorienting system, which was a longitudinal predictor of future socio-communicative skills at 21 months. Our combined transgenerational and longitudinal findings suggest that the early functionality of the stimulus-driven attentional network-redirecting attention from one event to another-could be directly connected to future social and communication development.

Investigating the Structure of the CESD-R and DASS-21 Across Adults with Low and High Levels of Autistic Traits

The current study examined factorial invariance of the Center for Epidemiologic Studies Depression Scale-Revised (CESD-R) and the Depression Anxiety Stress Scales-21 (DASS-21) using a convenience sample of 434 adults surveyed though Amazon Mechanical Turk. Participants were sorted into two groups based on their score on the Autism-Spectrum Quotient. Results indicated that the CESD-R did not demonstrate configural invariance. The DASS-21 demonstrated evidence of scalar invariance, indicating cross-group equality in factor loadings and factor intercepts. Findings suggest that the DASS-21 measures symptoms of depression, anxiety, and stress consistently across individuals with high and low levels of ASD-related traits, whereas the CESD-R may not be valid when assessing symptoms of depression in those with a high level of ASD-related traits.

Evaluative contexts facilitate implicit mentalizing: relation to the broader autism phenotype and mental health

One promising account for autism is implicit mentalizing difficulties. However, this account and even the existence of implicit mentalizing have been challenged because the replication results are mixed. Those unsuccessful replications may be due to the task contexts not being sufficiently evaluative. Therefore, the current study developed a more evaluative paradigm by implementing a prompt question. This was assessed in 60 non-autistic adults and compared with a non-prompt version. Additionally, parents of autistic children are thought to show a genetic liability to autistic traits and cognition and often report mental health problems, but the broader autism phenotype (BAP) is an under-researched area. Thus, we also aimed to compare 33 BAP and 26 non-BAP mothers on mentalizing abilities, autistic traits, compensation and mental health. Our results revealed that more evaluative contexts can facilitate implicit mentalizing in BAP and non-BAP populations, and thus improve task reliability and replicability. Surprisingly, BAP mothers showed better implicit mentalizing but worse mental health than non-BAP mothers, which indicates the heterogeneity in the broader autism phenotype and the need to promote BAP mothers' psychological resilience. The findings underscore the importance of contexts for implicit mentalizing and the need to profile mentalizing and mental health in BAP parents.

The Broad Autism Phenotype-International Test (BAP-IT): A two-domain-based test for the assessment of the broad autism phenotype

LAY ABSTRACT

The broad autism phenotype refers to a group of behaviors related to autism spectrum disorder, but that appear to a lesser extent. Its assessment has been performed through outdated broad autism phenotype/autism spectrum disorder definitions and tests. To address this problem, this study presents the development of a new test, the Broad Autism Phenotype-International Test, a 20-item measure consisting of two dimensions, SOCIAL-BAP and RIRE-BAP, targeting the two-domain operationalization of autism spectrum disorder in Spain and the United Kingdom. Unlike the Broad Autism Phenotype Questionnaire, this test received empirical support as a quick and effective broad autism phenotype measure that can facilitate both broad autism phenotype/autism spectrum disorder research and interventions. This is the first step to studying the BAP in several Spanish and English-speaking countries.

Maternal autistic traits and anxiety in children with typical development in Chinese families: a moderated mediation model of mothers' negative emotional expressions and child gender

Background

Prior studies have focused on the effects of maternal autistic traits on children with autism, but little attention has been paid to the effects of maternal autistic traits on typically developing children, while the mechanisms of the effects are not clear.

Objective

Given that, a moderated mediation model was conducted to examine the association between maternal autistic traits and typically developing children's anxiety and the underlying mechanisms.

Methods and results

Participants were 648 mother-child dyads in which these children had no autistic siblings. Mothers reported their autistic traits and negative emotional expressions in the family and children's anxiety. The results indicated that children's anxiety was predicted by maternal autistic traits. Mediating analysis revealed that mothers' negative emotional expressions partially mediated the association between their autistic traits and children's anxiety. The findings also indicated that child gender moderated the relationship between maternal emotional expressions and children's anxiety. Specifically, anxiety in girls was more strongly predicted by negative emotional expressions from their mothers than in boys.

Conclusion

These results have important theoretical and practical implications for reducing the adverse effect of maternal autistic traits on children's anxiety, especially for girls. The present study also reveals that maternal negative emotional expression is an important mechanism. Causal conclusions cannot be drawn based on cross-sectional research design, so it is necessary to conduct longitudinal studies in the future.

A sensory signature of unaffected biological parents predicts the risk of autism in their offspring

AIM

Despite the emphasis on sensory dysfunction phenotypes in the revised diagnostic criteria for autism spectrum disorder (ASD), there has been limited research, particularly in the field of neurobiology, investigating the concordance in sensory features between individuals with ASD and their genetic relatives. Therefore, our objective was to examine whether neurobehavioral sensory patterns could serve as endophenotypic markers for ASD.

METHODS

We combined questionnaire- and lab-based sensory evaluations with sensory fMRI measures to examine the patterns of sensory responsivity in 30 clinically diagnosed with ASD, 26 matched controls (CON), and 48 biological parents for both groups (27 parents of individuals with ASD [P-ASD] and 21 for individuals with CON [P-CON]).

RESULTS

The ASD and P-ASD groups had higher sensory responsivity and rated sensory stimuli as more unpleasant than the CON and P-CON groups, respectively. They also exhibited greater hemodynamic responses within the sensory cortices. Overlapping activations were observed within these sensory cortices in the ASD and P-ASD groups. Using a machine learning approach with robust prediction models across cohorts, we demonstrated that the sensory profile of biological parents accurately predicted the likelihood of their offspring having ASD, achieving a prediction accuracy of 71.4%.

CONCLUSIONS

These findings provide support for the hereditary basis of sensory alterations in ASD and suggest a potential avenue to improve ASD diagnosis by utilizing the sensory signature of biological parents, especially in families with a high risk of ASD. This approach holds promising prospects for early detection, even before the birth of the offspring.

Autistic traits predict social avoidance and distress: The chain mediating role of perceived stress and interpersonal alienation

Social avoidance and distress are the primary aspects of social anxiety. Nonautistic people with high levels of autistic traits are more likely to exhibit social avoidance and distress. However, research has yet to reveal how autistic traits induce social avoidance and distress. To fill this gap, the present study recruited 708 participants to complete the 25-item Autism Spectrum Quotient, Social Avoidance and Distress Scale, Chinese Perceived Stress Scale, and Interpersonal Alienation Subscale. The results indicated that autistic traits significantly predicted social avoidance and distress in nonautistic people. In addition, autistic traits induced social avoidance and distress through perceived stress and interpersonal alienation, respectively. Importantly, perceived stress and interpersonal alienation (including the subdimensions of interpersonal alienation: sense of loneliness, sense of social isolation, and alienation between family members) partially mediated the relationships between autistic traits and social avoidance and distress. Overall, autistic traits predict social avoidance and distress via perceived stress and interpersonal alienation. This finding extends the hypothetical model of clinical anxiety in autism spectrum disorders. Furthermore, reducing perceived stress and interpersonal alienation in nonautistic people with high levels of autistic traits may be a valid intervention method to prevent and eliminate their social avoidance and distress.

Towards a comprehensive approach to mentalization-based treatment for children with autism: integrating attachment, neurosciences, and mentalizing

Autism spectrum disorder (ASD) is diagnosed based on socio-communicative difficulties, which are believed to result from deficits in mentalizing, mainly evidenced by alterations in recognizing and responding to the mental states of others. In recent years, efforts have been made to develop mentalization-based treatment (MBT) models for this population. These models focus on enhancing individuals' ability to understand and reflect on their own mental states, as well as those of others. However, MBT approaches for people with ASD are limited by their existing theoretical background, which lacks a strong foundation grounded in neuroscience-based evidence properly integrated with attachment, and mentalizing. These are crucial aspects for understanding psychological processes in autism, and as such, they play a pivotal role in shaping the development of tailored and effective therapeutic strategies for this specific population. In this paper we review evidence related to the neurobiological, interpersonal, and psychological dimensions of autism and their implications for mentalizing processes. We also review previous mentalization-based frameworks on the psychosis continuum to provide a comprehensive understanding of attachment, neurobiology, and mentalization domains in therapeutic approaches for autism. After presenting a synthesis of the literature, we offer a set of clinical strategies for the work with children with autism. Finally, we provide recommendations to advance the field towards more robust models that can serve as a basis for evidence-based therapeutic strategies.

Associations between autism traits and family functioning over time in autistic and non-autistic children

LAY ABSTRACT

Little is known about family functioning over time when raising a child with autism traits, with or without a clinical autism diagnosis. Therefore, we asked caregivers-mostly parents-of a group of 168 children about the family functioning and the child's emotional and behavioral characteristics, as well as autistic traits, twice with about 1 year in between. For numerous reasons, the children were referred to youth mental health care centers, including child and adolescent psychiatric services. Care as usual was offered after the diagnostic assessment if a clinical diagnosis was the assessment outcome. Caregivers reported less problematic family functioning in children with fewer autism traits over time. The child's additional emotional or behavioral characteristics did not seem to influence this relation. Furthermore, we split the whole group into autistic children with a clinical autism diagnosis (58%) and non-autistic children with autism traits but without a clinical diagnosis (42%) to see whether we would find the same results in both groups. Surprisingly, the relation between family functioning and the level of a child's autism traits only held for the subgroup of non-autistic children with autism traits. Thus, raising children with autism traits without a clinical diagnosis may affect family functioning over time. We think that families might have difficulty understanding and adjusting to the autism traits of their children but are lacking the support that is exclusively offered to families of children with a clinical autism diagnosis. We must be cautious because we do not know whether there is a causal relation. Although further research is needed to explore and learn to understand this result, clinicians might consider offering support to families of children with subthreshold autism to prevent problems in family functioning. Because high autism trait levels in non-autistic children may be of a different origin than autism, for example, other neurodevelopmental or mental health problems, family training or support should be tailored to the child's underlying difficulties.

IL-6, homocysteine, and autism spectrum phenotypes: an investigation among adults with autism spectrum disorder and their first-degree relatives

BACKGROUND

The importance of recognizing different kinds of autism spectrum presentations among adults, including subthreshold forms and the broad autism phenotype (BAP), has been increasingly highlighted in recent studies. Meanwhile, the possible involvement of immune system deregulation and altered methylation/trans-sulfuration processes in autism spectrum disorder (ASD) is gaining growing attention, but studies in this field are mainly focused on children. In this framework, the aim of this study was to compare plasmatic concentrations of IL-6 and homocysteine (HCY) among adults with ASD, their first-degree relatives, and healthy controls (CTLs), investigating also possible correlations with specific autism symptoms.

METHODS

Plasma concentrations of IL-6 and HCY were measured in a group of adult subjects with ASD, their first-degree relatives (BAP group), and healthy controls (CTL). All participants were also evaluated with psychometric instruments.

RESULTS

IL-6 and HCY concentrations were significantly higher in the ASD group than in CTLs, while BAP subjects reported intermediate results. Significant correlations were reported between biochemical parameters and psychometric scales, particularly for the dimension of ruminative thinking.

CONCLUSIONS

These findings support the hypothesis of a key involvement of HCY-related metabolism and immune system alteration in autism spectrum pathophysiology. HCY and IL-6 seem to show different associations with specific autism dimensions.

Autism, pets, and the importance of seeing human

People often see the human in the nonhuman, a process called anthropomorphism. Anthropomorphism is particularly prolific regarding the humanization of pets. Some research suggests that people with autism may not anthropomorphize to the same degree as neurotypicals. In this study, we explored whether there were differences in how autistic and neurotypical pet owners anthropomorphized their pets. We also examined differences in levels of connectedness to nature and experiences of loneliness and how this corresponded to autistic traits in the entire sample. We found anthropomorphism was as common among autistic pet owners as in neurotypicals. However, autistic pet owners reported greater loneliness and were more likely to substitute pets for people. We also found that neurotypical pet owners rated pets more highly on physical, non-anthropomorphic traits (i.e., muscular, active). In contrast, autistic pet owners were likelier to rate pets equally between physical and anthropomorphic traits. Moreover, we found that anthropomorphism and connection to nature were positively correlated with autistic traits. These findings challenge accounts stating that individuals with autism may not anthropomorphize to the same degree as neurotypicals. Implications for animal-based interventions supporting adults on the spectrum are discussed.

Altered oculomotor flexibility is linked to high autistic traits

Autism is a multifaced disorder comprising sensory abnormalities and a general inflexibility in the motor domain. The sensorimotor system is continuously challenged to answer whether motion-contingent errors result from own movements or whether they are due to external motion. Disturbances in this decision could lead to the perception of motion when there is none and to an inflexibility with regard to motor learning. Here, we test the hypothesis that altered processing of gaze-contingent sensations are responsible for both the motor inflexibility and the sensory overload in autism. We measured motor flexibility by testing how strong participants adapted in a classical saccade adaptation task. We asked healthy participants, scored for autistic traits, to make saccades to a target that was displaced either in inward or in outward direction during saccade execution. The amount of saccade adaptation, that requires to shift the internal target representation, varied with the autistic symptom severity. The higher participants scored for autistic traits, the less they adapted. In order to test for visual stability, we asked participants to localize the position of the saccade target after they completed their saccade. We found the often-reported saccade-induced mis-localization in low Autistic Quotient (AQ) participants. However, we also found mislocalization in high AQ participants despite the absence of saccade adaptation. Our data suggest that high autistic traits are associated with an oculomotor inflexibility that might produce altered processing of trans-saccadic vision which might increase the perceptual overstimulation that is experienced in autism spectrum disorders (ASD).

Selective Attentional Networks Deficits in Parents of Children With Autism Spectrum Disorder: Evidence From Attention Network Test

OBJECTIVE

We primarily aimed to investigate the attention network function among parents of children with autism spectrum disorder (ASD) using the Attention Network Test (ANT). The secondary objective was to observe whether the three attention networks of all participants were related to each other.

METHODS

We included 28 parents of children with ASD and 28 well-matched parents of typically developing children. All participants underwent the neuropsychological assessment and ANT test. The three distinct attention networks, including alerting, orienting, and executive control, were also measured.

RESULTS

Compared with controls, parents of children with ASD showed less-efficient alerting and executive control network (all p<0.05), but not orienting network (p=0.74). No significant correlation was found between the alerting, orienting, and executive control network for either group.

CONCLUSION

Our findings showed that parents of children with ASD had deficits in alerting and executive control attention functions. The deficits are indications of a broad autism phenotype.

What are quantitative traits and how can they be used in autism research?

Quantitative traits are measurable characteristics distributed along a continuous scale thought to relate to underlying biology. There is growing interest in the use of quantitative traits in behavioral and psychiatric research, particularly in research on conditions diagnosed based on reports of behaviors, including autism. This brief commentary describes quantitative traits, including defining what they are, how we can measure them, and key considerations for their use in autism research. Examples of measures include behavioral report scales like the Social Responsiveness Scale and Broader Autism Phenotype Questionnaire, as well as biological measurements, like certain neuroimaging metrics; such measures can capture quantitative traits or constructs like the broader autism phenotype, social communication, and social cognition. Quantitative trait measures align with the Research Domain Criteria (RDoC) approach and can be used in autism research to help gain a better understanding of causal pathways and biological processes. They can also be used to aid identification of genetic and environmental factors involved in such pathways, and thereby lead to an understanding of influences on traits across the entire population. Finally, in some cases, they may be used to gauge treatment response, and assist screening and clinical characterization of phenotype. In addition, practical benefits of quantitative trait measures include improved statistical power relative to categorical classifications and (for some measures) efficiency. Ultimately, research across autism fields may benefit from incorporating quantitative trait measures as a complement to categorical diagnosis to advance understanding of autism and neurodevelopment.

Event-Related Potentials in Assessing Visual Speech Cues in the Broader Autism Phenotype: Evidence from a Phonemic Restoration Paradigm

Audiovisual speech perception includes the simultaneous processing of auditory and visual speech. Deficits in audiovisual speech perception are reported in autistic individuals; however, less is known regarding audiovisual speech perception within the broader autism phenotype (BAP), which includes individuals with elevated, yet subclinical, levels of autistic traits. We investigate the neural indices of audiovisual speech perception in adults exhibiting a range of autism-like traits using event-related potentials (ERPs) in a phonemic restoration paradigm. In this paradigm, we consider conditions where speech articulators (mouth and jaw) are present (AV condition) and obscured by a pixelated mask (PX condition). These two face conditions were included in both passive (simply viewing a speaking face) and active (participants were required to press a button for a specific consonant-vowel stimulus) experiments. The results revealed an N100 ERP component which was present for all listening contexts and conditions; however, it was attenuated in the active AV condition where participants were able to view the speaker's face, including the mouth and jaw. The P300 ERP component was present within the active experiment only, and significantly greater within the AV condition compared to the PX condition. This suggests increased neural effort for detecting deviant stimuli when visible articulation was present and visual influence on perception. Finally, the P300 response was negatively correlated with autism-like traits, suggesting that higher autistic traits were associated with generally smaller P300 responses in the active AV and PX conditions. The conclusions support the finding that atypical audiovisual processing may be characteristic of the BAP in adults.

The role of the broader autism phenotype in anxiety and depression in college-aged adults

The current study examines the relationship between the presence of autistic traits and anxiety and mood disorders in young adults from different racial groups. A representative sample from a predominately white university (2,791 non-Hispanic White (NHW) and 185 Black students) completed the broad autism phenotype questionnaire (BAPQ), a measure of depression (Patient Health Questionnaire, PHQ-9), and anxiety (Generalized Anxiety Disorder, GAD-7). Statistical Package for Social Sciences (SPSS) was used to perform two multiple regression analyses to determine the association between race, BAPQ score and anxiety and depression symptoms. The current study found a stronger association between autistic traits had depression and anxiety symptoms in Black participants than did NHW participants. These findings underscore the association between autistic traits and anxiety and depression in Black communities, and the need for further studies on this topic area. Additionally, it highlights the importance of improving access to mental health care for this population.

Autistic traits distribution in different psychiatric conditions: A cluster analysis on the basis of the Adult Autism Subthreshold Spectrum (AdAS Spectrum) questionnaire

Increasing interest is being paid on full-threshold and sub-threshold autism spectrum conditions among adults. Sub-threshold autistic traits (AT) seem to be distributed in a continuum from the clinical to the general population, being particularly higher among subjects with other psychiatric disorders. The aim of the present study was to evaluate the distribution of AT in a sample of subjects with different psychiatric conditions by means of a cluster analysis on the basis of the score reported to the AdAS Spectrum instrument. A total of 738 subjects recruited by seven Italian Universities were divided in 5 groups depending on the clinical diagnosis: Autism spectrum disorder (ASD), subthreshold ASD symptoms (partial ASD), Bipolar disorder (BD), Feeding and eating disorders (FED), and controls (CTLs). All subjects were assessed with the AdAS Spectrum. The cluster analysis identified 3 clusters: the high, medium and low autism clusters. The Restricted interests and rumination domain reported the highest influence in forming the clusters. The high, medium and low autism clusters were respectively more represented in the ASD, partial ASD and CTL groups. The clusters were represented intermediately in the FED and BD groups, confirming the presence of intermediate levels of AT in these clinical populations.

Measuring Social Camouflaging in Individuals with High Functioning Autism: A Literature Review

In the recent years, growing attention has been paid to the use of camouflaging strategies by adult populations suffering from autism spectrum disorder (ASD) with milder manifestations and without intellectual impairment, which may lead to a delay in diagnosis or even a misdiagnosis. In fact, high-functioning ASD individuals were reported to be more aware of their communication difficulties and were more likely make considerable efforts to adjust their behavior to conventional rules of non-autistic individuals, learning to imitate other non-ASD individuals. Moreover, females reported a higher frequency of camouflaging strategies, suggesting a role of camouflaging in the gender gap of the ASD diagnosis. Although camouflaging strategies can sometimes grant a better level of adjustment, even resulting in a hyper-adaptive behavior, they are also often correlated with negative mental health consequences due to the long-term stress associated with continuous attempts to adapt in day-to-day life. In this framework, the aim of the present work was to review the available studies that assessed the presence and correlates of camouflaging strategies in individuals with ASD. Although the literature available on the topic is still scarce, some interesting correlations between camouflaging and anxious and depressive symptoms, as well as suicidality, were highlighted. In particular, the controversial and sometime opposite thoughts and results about camouflaging may be clarified and integrated in light of a dimensional approach to psychopathology.

Reading the room: Autistic traits, gaze behaviour, and the ability to infer social relationships

Individuals high in autistic traits can have difficulty understanding verbal and non-verbal cues, and may display atypical gaze behaviour during social interactions. The aim of this study was to examine differences among neurotypical individuals with high and low levels of autistic traits with regard to their gaze behaviour and their ability to assess peers' social status accurately. Fifty-four university students who completed the 10-item Autism Quotient (AQ-10) were eye-tracked as they watched six 20-second video clips of people ("targets") involved in a group decision-making task. Simulating natural, everyday social interactions, the video clips included moments of debate, humour, interruptions, and cross talk. Results showed that high-scorers on the AQ-10 (i.e., those with more autistic traits) did not differ from the low-scorers in either gaze behaviour or assessing the targets' relative social status. The results based on this neurotypical group of participants suggest that the ability of individuals high in autistic traits to read social cues may be preserved in certain tasks crucial to navigating day-to-day social relationships. These findings are discussed in terms of their implications for theory of mind, weak central coherence, and social motivation theories of autism.

"Peas in a pod": Oral History Reflections on Autistic Identity in Family and Community by Late-Diagnosed Adults

In this paper, we report on a participatory oral history study documenting the lives of late-diagnosed autistic adults in Australia. We interviewed 26 autistic adults about their life history and the impact of late diagnosis. All were diagnosed after the age of 35, growing up in an era when autism was not well known. Using reflexive thematic analysis, we uncovered a rich body of reflections on shared Autistic identity and identified three major themes within that data set: 'conceptualising the Autistic family', 'creating Autistic community', and 'contesting Autistic identity'. Overall, the study provides insights into the active creation of shared Autistic identity and the importance of Autistic community to these late-diagnosed autistic adults.

Vigilance or avoidance: How do autistic traits and social anxiety modulate attention to the eyes?

Introduction

Social anxiety disorder (SAD) and autism spectrum disorder (ASD) are highly overlapping in symptoms and have a high rate of comorbidity, posing challenges in diagnosis and intervention for both disorders. Both disorders are linked to abnormal attention to the eyes, yet how they interactively modulate the attentional process to the eyes remains unclear.

Methods

In this study, we explored how autistic traits and social anxiety in college students separately and together affected different temporal stages of attention to the eyes. Participants were instructed to view virtual faces for 10 s and make an emotional judgment, while their eye movements were recorded.

Results

We found that social anxiety and autistic traits affected different temporal stages of eye-looking. Social anxiety only affected the first fixation duration on the eyes, while autistic traits were associated with eye avoidance at several time points in the later stage. More importantly, we found an interactive effect of autistic traits and social anxiety on the initial attention to the eyes: Among people scoring high on autistic traits, social anxiety was related to an early avoidance of the eyes as well as attention maintenance once fixated on the eyes.

Discussion

Our study suggests the separate and interactive roles of social anxiety and autistic traits in attention to the eyes. It contributes to a deeper understanding of the mechanisms of social attention in both SAD and ASD and highlights the application of psychiatric diagnoses using eye-tracking techniques.

Dynamic eye avoidance patterns in the high autistic traits group: An eye-tracking study

Introduction

Reduced fixation to the eye area is the main characteristic of social deficits associated with Autism Spectrum Disorder; a similar pattern may exist in individuals with high autistic traits. However, their scanning patterns to the eye area of emotional faces are still unclear on the time scale.

Methods

In the present study, we recruited 46 participants and divided them into the high autistic traits (HAT) group (23 participants) and the low autistic traits (LAT) group (20 participants) based on their Autism Spectrum Quotient (AQ) scores. Moreover, we captured their eye movement patterns when observing different angular emotional faces. We extracted the proportional fixation time to the eye area under different time windows.

Results

The results showed that the fixation time of the HAT group was always significantly smaller than that of the LAT group (p < 0.05), and the difference between the two groups increased in the middle and late stages of face presentation. The results of the linear regression analysis showed that the proportional fixation time was negatively correlated with AQ scores (p < 0.05), indicating that the proportional fixation time to the eye area could be a potential indicator to measure the level of autistic traits. We then calculated the latency to orient the eye area and the latency to disengage the eye area to explore the priority of observation of the eyes. The results showed that compared with the LAT group, the HAT group has a longer latency to orient the eye area (p < 0.05) and has longer latency to disengage the eye area (p < 0.05), illustrating that the HAT group saw the eyes more slowly and left them faster.

Does the current state of biomarker discovery in autism reflect the limits of reductionism in precision medicine? Suggestions for an integrative approach that considers dynamic mechanisms between brain, body, and the social environment

Over the past decade, precision medicine has become one of the most influential approaches in biomedical research to improve early detection, diagnosis, and prognosis of clinical conditions and develop mechanism-based therapies tailored to individual characteristics using biomarkers. This perspective article first reviews the origins and concept of precision medicine approaches to autism and summarises recent findings from the first "generation" of biomarker studies. Multi-disciplinary research initiatives created substantially larger, comprehensively characterised cohorts, shifted the focus from group-comparisons to individual variability and subgroups, increased methodological rigour and advanced analytic innovations. However, although several candidate markers with probabilistic value have been identified, separate efforts to divide autism by molecular, brain structural/functional or cognitive markers have not identified a validated diagnostic subgroup. Conversely, studies of specific monogenic subgroups revealed substantial variability in biology and behaviour. The second part discusses both conceptual and methodological factors in these findings. It is argued that the predominant reductionist approach, which seeks to parse complex issues into simpler, more tractable units, let us to neglect the interactions between brain and body, and divorce individuals from their social environment. The third part draws on insights from systems biology, developmental psychology and neurodiversity approaches to outline an integrative approach that considers the dynamic interaction between biological (brain, body) and social mechanisms (stress, stigma) to understanding the origins of autistic features in particular conditions and contexts. This requires 1) closer collaboration with autistic people to increase face validity of concepts and methodologies; (2) development of measures/technologies that enable repeat assessment of social and biological factors in different (naturalistic) conditions and contexts, (3) new analytic methods to study (simulate) these interactions (including emergent properties), and (4) cross-condition designs to understand which mechanisms are transdiagnostic or specific for particular autistic sub-populations. Tailored support may entail both creating more favourable conditions in the social environment and interventions for some autistic people to increase well-being.

Autistic Traits, Arousal, and Gender Features in a Nonclinical Sample of Italian Adolescents

(1) Background: Subthreshold autism is a sub-clinical pattern of autism spectrum disorder-like (ASD-like) traits, including poor social skills, cognitive rigidity, anxiety, and aloofness. These ASD-like traits are significantly more prevalent among parents and relatives of participants with autism; however, evidence suggests that subclinical autistic traits are not restricted to the family members of individuals with autism but rather are continuously distributed in the general population. Though the autistic subclinical form is perhaps prevalent among adults, little attention has been paid to the association between autistic traits and global functioning in adolescence. The aim of the present study is to investigate the subthreshold autism phenotype in adolescence and its relationship with arousal correlates, exploring gender differences emerging in the sample. (2) Methods: A sample of 725 students (293 males and 432 females; mean age 17.19) were recruited from three high schools in Southern Italy. They were assessed by the following instruments: Autism Spectrum Quotient, Adult Autism Subthreshold Spectrum, Ritvo Autism and Asperger Diagnostic Scale 14, and Hyperarousal Scale. (3) Results: In males, significant direct correlations between all dimensions of arousal and all variables related to autistic traits emerged except for the correlations between the H-Scale "Introspection score", the AQ questionnaire "Total score" (p = 0.094), and the AdAS-Spectrum questionnaire "Empathy factor" (p = 0.210); in females, significant positive correlations between all dimensions of arousal and all variables related to autistic traits emerged. (4) Conclusions: In the sample of adolescents with subclinical profiles of autistic traits, the Empathy factor of the AdAS Spectrum questionnaire was significantly higher in the male group than in the female group, underscoring lower empathic abilities in the former group. In the male group, the empathy factor did not have a statistically significant correlation with the H-scale introspection factor or with the autistic traits measured by AQ. We suppose that in male adolescents, another hypothetical factor seems to intervene in the relationship between autistic traits and arousal. Otherwise, empathy is a preponderant factor closely related to hyper-arousal responses in female adolescents with autistic traits.

High-Risk Siblings without Autism: Insights from a Clinical and Eye-Tracking Study

Joint attention (JA)-the human ability to coordinate our attention with that of other people-is impaired in the early stage of Autism Spectrum Disorder (ASD). However, little is known about the JA skills in the younger siblings of children with ASD who do not develop ASD at 36 months of age [high-risk (HR)-noASD]. In order to advance our understanding of this topic, a prospective multicenter observational study was conducted with three groups of toddlers (age range: 18-33 months): 17 with ASD, 19 with HR-noASD and 16 with typical development (TD). All subjects underwent a comprehensive clinical assessment and an eye-tracking experiment with pre-recorded stimuli in which the visual patterns during two tasks eliciting initiating joint attention (IJA) were measured. Specifically, fixations, transitions and alternating gaze were analyzed. Clinical evaluation revealed that HR-noASD subjects had lower non-verbal cognitive skills than TD children, while similar levels of restricted and repetitive behaviors and better social communication skills were detected in comparison with ASD children. Eye-tracking paradigms indicated that HR-noASD toddlers had visual patterns resembling TD in terms of target-object-to-face gaze alternations, while their looking behaviors were similar to ASD toddlers regarding not-target-object-to-face gaze alternations. This study indicated that high-risk, unaffected siblings displayed a shared profile of IJA-eye-tracking measures with both ASD patients and TD controls, providing new insights into the characterization of social attention in this group of toddlers.

No evidence for superior distractor filtering amongst individuals high in autistic-like traits

Autistic individuals and individuals with high levels of autistic-like traits often show better visual search performance than their neurotypical peers. The present work investigates whether this advantage stems from increased ability to filter out distractors. Participants with high or low levels of autistic-like traits completed an attentional blink task in which trials varied in target-distractor similarity. The results showed no evidence that high levels of autistic-like traits were associated with superior distractor filtering (indexed by the difference in the size of the attentional blink across the high- and low-similarity distractors). This suggests that search advantages seen in previous studies are likely linked to other mechanisms such as enhanced pre-attentive scene processing, better decision making, or more efficient response selection.

The Clinical Implications of the Academic Performance of the Siblings of Individuals With Autism Spectrum Disorder

We all know that autism spectrum disorder (ASD) can affect academic performance. Many children with autism face different challenges at school. However, less attention is paid to the siblings of autistic children, who are at a high risk of ASD or the broad autism phenotype (BAP). Recent data also shows that many siblings of ASD children suffer from neurodevelopmental disorders, mental health problems as well as poor academic performance. This review will look at the possible etiologies of the poor school performance of autistic children's siblings, with an emphasis on the challenges they face. We will also highlight the clinical implications of these findings, and the possible solutions that can help this vulnerable group.

Psychometric properties of the Persian version of the Autism-Spectrum Quotient (AQ-19) with Iranian university students

Studies suggest that autistic traits are widespread among the general population and, in this regard, the short form of the Autism-Spectrum Quotient (AQ), the AQ-28, was developed to measure autistic traits. The present study examines the factor structure, internal consistency, and convergent validity of the Persian version of the AQ-28 with 691 Iranian university students (M_age = 28.67, SD = 8.57, 57.3% women) who were recruited online and completed the AQ-28 and Symptom Checklist (SCL-25) measures. Confirmatory factor analysis results yielded a four-factor model, which was internally consistent and demonstrated hypothesized correlations with the external correlates of interest (e.g., anxiety, depression, and phobia). Results support the Persian version of the AQ with 19 items (AQ-19) as a measure with sound psychometrics to be used in studies with Iranian university students.

Clinical autism subscales have common genetic liabilities that are heritable, pleiotropic, and generalizable to the general population

The complexity of autism's phenotypic spectra is well-known, yet most genetic research uses case-control status as the target trait. It is undetermined if autistic symptom domain severity underlying this heterogeneity is heritable and pleiotropic with other psychiatric and behavior traits in the same manner as autism case-control status. In N = 6064 autistic children in the SPARK cohort, we investigated the common genetic properties of twelve subscales from three clinical autism instruments measuring autistic traits: the Social Communication Questionnaire (SCQ), the Repetitive Behavior Scale-Revised (RBS-R), and the Developmental Coordination Disorder Questionnaire (DCDQ). Educational attainment polygenic scores (PGS) were significantly negatively correlated with eleven subscales, while ADHD and major depression PGS were positively correlated with ten and eight of the autism subscales, respectively. Loneliness and neuroticism PGS were also positively correlated with many subscales. Significant PGS by sex interactions were found-surprisingly, the autism case-control PGS was negatively correlated in females and had no strong correlation in males. SNP-heritability of the DCDQ subscales ranged from 0.04 to 0.08, RBS-R subscales ranged from 0.09 to 0.24, and SCQ subscales ranged from 0 to 0.12. GWAS in SPARK followed by estimation of polygenic scores (PGS) in the typically-developing ABCD cohort (N = 5285), revealed significant associations of RBS-R subscale PGS with autism-related behavioral traits, with several subscale PGS more strongly correlated than the autism case-control PGS. Overall, our analyses suggest that the clinical autism subscale traits show variability in SNP-heritability, PGS associations, and significant PGS by sex interactions, underscoring the heterogeneity in autistic traits at a genetic level. Furthermore, of the three instruments investigated, the RBS-R shows the greatest evidence of genetic signal in both (1) autistic samples (greater heritability) and (2) general population samples (strongest PGS associations).

Eating disorders and autism spectrum: links and risks

In the last decades, increasing attention has been provided to socio-cultural and neurobiological factors involved in the psychopathology of feeding and eating disorders (FED), encouraging a multifactorial approach. In this framework, several authors stressed an association between FED and other kinds of psychiatric disorders from both a psychopathological and a neurobiological point of view. In particular, many promising contributions are focusing on the possible link between FED and autism spectrum disorder (ASD). Growing interest about this association rose from the frequently reported evidence of ASD-like traits amongst FED patients and abnormal eating behaviors amongst patients with ASD. This narrative review overview aims to summarize the most relevant findings about the overlap between different kinds of FED and the autism spectrum, taking into account the most recent hypotheses about the psychopathology of both these conditions. While most of the studies focused on anorexia nervosa, both ASD and autistic traits seem to be detectable also in other kinds of FED. In addition, the recently increased interest toward a dimensional approach to psychopathology led to progressively broadening the concept of ASD, focusing on its subthreshold and gender-specific manifestations and on its link with other psychiatric conditions, including FED. Globally the studies summarized here provide further support to theoretical models featuring a neurodevelopmental approach for mental disorders. In particular, FED have been conceptualized as a possible psychopathological trajectory of a neurodevelopmental alteration, toward which female gender would act as one of many predisposing factors.

Decreased Empathy Response to Other's Pain in Parents of Children With Autism Spectrum Disorder

We aimed to investigate pain empathy ability and self-reported empathy among parents of children with autism spectrum disorder (ASD). Twenty-four parents of children with ASD and 26 parents of typically developing children completed the Empathy Quotient (EQ) self-report scale and responded to painful or neutral images during an empathy-for-pain paradigm test. Parents of children with ASD had lower EQ scores, lower accuracy, and longer reaction time (RT) for pain empathy task response (all p < 0.05) compared with controls. There was a negative relationship between cognitive empathy, social skills, total EQ scores, and RT of response in parents of children with ASD. Our findings indicate that self-reported empathy deficits and decreased empathy response to the sight of others' pain in parents of children with ASD are part of a broader autistic phenotype.

Kynurenine pathway and autism spectrum phenotypes: an investigation among adults with autism spectrum disorder and their first-degree relatives

BACKGROUND

Increasing literature highlighted alterations of tryptophan (TRP) metabolism and kynurenine (KYN) pathway in children with autism spectrum disorder (ASD). However, no study specifically focused on adult samples. Meanwhile, several authors stressed the relevance of investigating neurobiological correlates of adult forms of ASD and of those subthreshold ASD manifestations frequently found in relatives of ASD probands, known as broad autism phenotype (BAP). This work aimed to evaluate circulating levels of TRP and metabolites of KYN pathway in a sample of ASD adults, their first-degree relatives and controls (CTLs), investigating also the correlations between biochemical variables' levels and ASD symptoms.

METHODS

A sample of ASD adults, together with a group of first-degree relatives (BAP group) and unrelated CTLs were assessed by means of psychometric scales. Circulating levels of TRP, KYN, quinolinic acid (QA), and kynurenic acid (KYNA) were assessed in all subjects.

RESULTS

ASD patients reported significantly higher total scores than the other groups on all psychometric scales. BAP subjects scored significantly higher than CTLs. ASD patients reported significantly lower TRP levels than BAP and CTL groups. Moreover, significantly lower levels of KYNA were reported in both ASD and BAP groups than in CTLs. Specific patterns of associations were found between autism symptoms and biochemical variables.

CONCLUSIONS

Our findings confirm in adult samples the presence of altered TRP metabolism through KYN pathway. The intermediate alterations reported among relatives of ASD patients further stress the presence of a continuum between subthreshold and full-threshold ASD phenotypes also from a biochemical perspective.

Applying a Rasch model to the Broad Autism Phenotype Questionnaire: item severity analysis and differential test functioning of the English and Spanish versions

The broad autism phenotype (BAP) represents the elevated but nonclinical levels of autism-related expressions expanding them beyond the disorder threshold towards the general population and it is assessed worldwide using the Broad Autism Phenotype Questionnaire. In this study, we applied a Rasch item response approach to the Spanish and the English BAPQ versions. This approach allows us to test the proper functioning of each version, estimate which BAP behaviours are more likeable at different levels of severity, and study whether BAPQ item’s severities and orders could be considered equivalent between both versions. A Spanish community sample of 970 participants and an English of 533 ones completed either the Spanish or the English version of the BAPQ. The results revealed a lack of unidimensionality of the Pragmatic Language subscale in both tests and the Rigid subscale in the English version. Both Aloof subscale versions and the Spanish Rigid demonstrated adequate properties but with several items showing differential functioning in the case of Aloof. We conclude by highlighting the necessity of BAP measurements paralleling the current autism spectrum disorder structure, following the severity-dimensional conceptualization (behaviours are continuously distributed according to their severity), and suitable for being adapted to different languages.

Characterizing Emotion Recognition and Theory of Mind Performance Profiles in Unaffected Siblings of Autistic Children

Emotion recognition skills and the ability to understand the mental states of others are crucial for normal social functioning. Conversely, delays and impairments in these processes can have a profound impact on capability to engage in, maintain, and effectively regulate social interactions. Therefore, this study aimed to compare the performance of 42 autistic children (Mage = 8.25 years, SD = 2.22), 45 unaffected siblings (Mage = 8.65 years, SD = 2.40), and 41 typically developing (TD) controls (Mage = 8.56 years, SD = 2.35) on the Affect Recognition (AR) and Theory of Mind (TOM) subtests of the Developmental Neuropsychological Assessment Battery. There were no significant differences between siblings and TD controls. Autistic children showed significantly poorer performance on AR when compared to TD controls and on TOM when compared to both TD controls and unaffected siblings. An additional comparison of ASD, unaffected sibling and TD control subsamples, matched on full-scale IQ, revealed no group differences for either AR or TOM. AR and TOM processes have received less research attention in siblings of autistic children and remain less well characterized. Therefore, despite limitations, findings reported here contribute to our growing understanding of AR and TOM abilities in siblings of autistic children and highlight important future research directions.

Psychometric properties of the Korean version of the Broad Autism Phenotype Questionnaire

We validated a Korean version of the Broad Autism Phenotype Questionnaire (BAPQ) by investigating its factor structure with a nonclinical sample. Participants were 495 undergraduate students in Korea. The results show that the Korean version of the BAPQ (K-BAPQ) had adequate internal consistency (Cronbach's α = .75–.89). Correlations between scores on the BAPQ and on the Autism-Spectrum Quotient were statistically significant and moderate-to-high in size. Confirmatory factor analysis did not show a satisfactory fit with the factor structure of the original BAPQ. Exploratory factor analysis demonstrated that a three-factor structure could be suitable in our sample, but the internal structure of the BAPQ still needs further examination. We recommend use of the total score of the K-BAPQ, as opposed to those of the subscales alone, and suggest that further research is needed to confirm the factor structure.

Differences in cortical processing of facial emotions in broader autism phenotype

Autism Spectrum Disorder (ASD) is a heterogeneous condition that affects face perception. Evidence shows that there are differences in face perception associated with the processing of low spatial frequency (LSF) and high spatial frequency (HSF) of visual stimuli between non-symptomatic relatives of individuals with autism (broader autism phenotype, BAP) and typically developing individuals. However, the neural mechanisms involved in these differences are not fully understood. Here we tested whether face-sensitive event related potentials could serve as neuronal markers of differential spatial frequency processing, and whether these potentials could differentiate non-symptomatic parents of children with autism (pASD) from parents of typically developing children (pTD). To this end, we performed electroencephalographic recordings of both groups of parents while they had to recognize emotions of face pictures composed of the same or different emotions (happiness or anger) presented in different spatial frequencies. We found no significant differences in the accuracy between groups but lower amplitude modulation in the Late Positive Potential activity in pASD. Source analysis showed a difference in the right posterior part of the superior temporal region that correlated with ASD symptomatology of the child. These results reveal differences in brain processing of recognition of facial emotion in BAP that could be a precursor of ASD.

Validation of the Italian version of the Camouflaging Autistic Traits Questionnaire (CAT-Q) in a University population

The Camouflaging Autistic Traits Questionnaire (CAT-Q) is an instrument recently developed and validated in English for measuring social camouflaging. While increasing research is focusing on camouflaging behaviours often used for masking autistic traits in social contexts, the CAT-Q remains the only self-report instrument in this field. We aimed to validate the Italian version of the CAT-Q, further testing its validity and reliability in a large Italian University population (N = 2439). We employed the Adult Autism Subthreshold Spectrum (AdAS Spectrum) for assessing autism spectrum conditions. The CAT-Q demonstrated excellent internal consistency and test-retest reliability, as well as strong correlations with the AdAS Spectrum. Our results confirm that the CAT-Q is a valuable instrument for evaluating social camouflaging.

Autism: A model of neurodevelopmental diversity informed by genomics

Definitions of autism are constantly in flux and the validity and utility of diagnostic criteria remain hotly debated. The boundaries of autism are unclear and there is considerable heterogeneity within autistic individuals. Autistic individuals experience a range of co-occurring conditions notably including other childhood onset neurodevelopmental conditions such as intellectual disability, epilepsy and ADHD, but also other neuropsychiatric conditions. Recently, the neurodiversity movement has challenged the conception of autism as a medical syndrome defined by functional deficits. Whereas others have argued that autistic individuals with the highest support needs, including those with intellectual disability and limited functional communication, are better represented by a medical model. Genomic research indicates that, rather than being a circumscribed biological entity, autism can be understood in relation to two continua. On the one hand, it can be conceived as lying on a continuum of population variation in social and adaptive functioning traits, reflecting in large part the combination of multiple alleles of small effect. On the other, it can be viewed as lying on a broader neurodevelopmental continuum whereby rare genetic mutations and environmental risk factors impact the developing brain, resulting in a diverse spectrum of outcomes including childhood-onset neurodevelopmental conditions as well as adult-onset psychiatric conditions such as schizophrenia. This model helps us understand heterogeneity within autism and to reconcile the view that autism is a part of natural variability, as advocated by the neurodiversity movement, with the presence of co-occurring disabilities and impairments of function in some autistic individuals.

The DSM-5 introduction of the Social (Pragmatic) Communication Disorder as a new mental disorder: a philosophical review

The latest edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) included the Social (Pragmatic) Communication Disorder (SPCD) as a new mental disorder characterized by deficits in pragmatic abilities. Although the introduction of SPCD in the psychiatry nosography depended on a variety of reasons-including bridging a nosological gap in the macro-category of Communication Disorders-in the last few years researchers have identified major issues in such revision. For instance, the symptomatology of SPCD is notably close to that of (some forms of) Autism Spectrum Disorder (ASD). This opens up the possibility that individuals with very similar symptoms can be diagnosed differently (with either ASD or SPCD) and receive different clinical treatments and social support. The aim of this paper is to review recent debates on SPCD, particularly as regards its independence from ASD. In the first part, we outline the major aspects of the DSM-5 nosological revision involving ASD and SPCD. In the second part, we focus on the validity and reliability of SPCD. First, we analyze literature on three potential validators of SPCD, i.e., etiology, response to treatment, and measurability. Then, we turn to reliability issues connected with the introduction of the grandfather clause and the use of the concepts of spectrum and threshold in the definition of ASD. In the conclusion, we evaluate whether SPCD could play any role in contemporary psychiatry other than that of an independent mental disorder and discuss the role that non-epistemic factors could play in the delineation of the future psychiatry nosography.

Improving the measurement of alexithymia in autistic adults: a psychometric investigation of the 20-item Toronto Alexithymia Scale and generation of a general alexithymia factor score using item response theory

BACKGROUND

Alexithymia, a personality trait characterized by difficulties interpreting emotional states, is commonly elevated in autistic adults, and a growing body of literature suggests that this trait underlies several cognitive and emotional differences previously attributed to autism. Although questionnaires such as the 20-item Toronto Alexithymia Scale (TAS-20) are frequently used to measure alexithymia in the autistic population, few studies have investigated the psychometric properties of these questionnaires in autistic adults, including whether differential item functioning (I-DIF) exists between autistic and general population adults.

METHODS

This study is a revised version of a previous article that was retracted due to copyright concerns (Williams and Gotham in Mol Autism 12:1-40). We conducted an in-depth psychometric analysis of the TAS-20 in a large sample of 743 cognitively able autistic adults recruited from the Simons Foundation SPARK participant pool and 721 general population controls enrolled in a large international psychological study. The factor structure of the TAS-20 was examined using confirmatory factor analysis, and item response theory was used to generate a subset of the items that were strong indicators of a "general alexithymia" factor. Correlations between alexithymia and other clinical outcomes were used to assess the nomological validity of the new alexithymia score in the SPARK sample.

RESULTS

The TAS-20 did not exhibit adequate model fit in either the autistic or general population samples. Empirically driven item reduction was undertaken, resulting in an 8-item general alexithymia factor score (GAFS-8, with "TAS" no longer referenced due to copyright) with sound psychometric properties and practically ignorable I-DIF between diagnostic groups. Correlational analyses indicated that GAFS-8 scores, as derived from the TAS-20, meaningfully predict autistic trait levels, repetitive behaviors, and depression symptoms, even after controlling for trait neuroticism. The GAFS-8 also presented no meaningful decrement in nomological validity over the full TAS-20 in autistic participants.

LIMITATIONS

Limitations of the current study include a sample of autistic adults that was majority female, later diagnosed, and well educated; clinical and control groups drawn from different studies with variable measures; only 16 of the TAS-20 items being administered to the non-autistic sample; and an inability to test several other important psychometric characteristics of the GAFS-8, including sensitivity to change and I-DIF across multiple administrations.

CONCLUSIONS

These results indicate the potential of the GAFS-8 to robustly measure alexithymia in both autistic and non-autistic adults. A free online score calculator has been created to facilitate the use of norm-referenced GAFS-8 latent trait scores in research applications (available at https://asdmeasures.shinyapps.io/alexithymia ).

Synaesthesia as a model system for understanding variation in the human mind and brain

The aim of this article is to reposition synaesthesia as model system for understanding variation in the construction of the human mind and brain. People with synaesthesia inhabit a remarkable mental world in which numbers can be coloured, words can have tastes, and music is a visual spectacle. Key questions remain unanswered about why it exists, and how the study of synaesthesia might inform theories of the human mind. This article argues we need to rethink synaesthesia as not just representing exceptional experiences, but as a product of an unusual neurodevelopmental cascade from genes to brain to cognition of which synaesthesia is only one outcome. Specifically, differences in the brains of synaesthetes support a distinctive way of thinking (enhanced memory, imagery etc.) and may also predispose towards particular clinical vulnerabilities. In effect, synaesthesia can act as a paradigmatic example of a neuropsychological approach to individual differences.