Commentary: 'Camouflaging' in autistic people - reflection on Fombonne (2020)

Camouflaging, internalized stigma, and mental health in the general population

BACKGROUND

Camouflaging, the strategies that some autistic people use to hide their differences, has been hypothesized to trigger mental health ramifications. Camouflaging might reflect ubiquitous impression management experiences that are not unique to autistic people and similarly impact the mental health of non-autistic people.

AIMS

We first examined whether individuals in the general population camouflage and manage impressions while experiencing mental health repercussions, and how gender and neurodivergent traits modified these associations. We then assessed how camouflaging and impression management arose from internalized stigma, and their inter-relationships in shaping mental health outcomes.

METHODS

Data were collected from 972 adults from a representative U.S. general population sample, with measures pertaining to camouflaging, impression management, mental health, internalized stigma, and neurodivergent traits. Multivariate hierarchical regression and moderated mediation analyses were used to address the two research aims.

RESULTS

Both camouflaging and self-presentation (a key component of impression management) were associated with mental health presentations in the general population, which overlapped with those previously reported in autistic people. These associations were more pronounced in women compared with men and were of different directions for individuals with higher autistic traits versus higher ADHD traits. Internalized stigma might be a key stressor that could elicit camouflaging and impression management through social anxiety, which in turn might lead to adverse mental health outcomes.

CONCLUSIONS

These findings advance the conceptual clarity and clinical relevance of camouflaging and impression management across social and neurodiverse groups in the general population. The ramifications of camouflaging and impression management underscore the need to alleviate internalized stigma for better mental health across human groups.

Validation of the camouflaging autistic traits questionnaire short form (CATQ-SF)

BACKGROUND

Camouflaging of autistic traits involves hiding or compensating for autistic characteristics, often due to stigma or a desire to fit in with others. This behaviour has been associated with mental health issues in autistic individuals. The 2 5-item Camouflaging Autistic Traits Questionnaire (CAT-Q) is the most commonly used self-report measure of camouflaging. In this study, a 9-item short form version was developed for use in clinical and research settings.

AIMS

To construct and psychometrically validate a brief self-report measure of camouflaging.

METHOD

The Camouflaging Autistic Traits Questionnaire - Short Form (CATQ-SF) was developed and its factor structure and psychometric properties were evaluated in two studies. Study 1 used a large, online sample of autistic and non-autistic adults (N = 832) to evaluate the factor structure, psychometric properties, and measurement invariance of the CATQ-SF. Study 2 used an independent sample of autistic and non-autistic adults (N = 80) to test Study 1's findings.

RESULTS

In Study 1, evidence for a three-factor structure was observed, with good internal consistency (combined autistic & non-autistic α = 0.84). In addition, the instrument demonstrated measurement invariance, and reliably predicted higher levels of autistic traits. In Study 2, the 3-factor structure was replicated, and good internal consistency was again observed (combined autistic and non-autistic α = 0.89). In both studies, psychometric properties were of similar or higher validity compared to the full-form CAT-Q.

CONCLUSIONS

The CATQ-SF can be used by clinicians and researchers to measure camouflaging in autistic and non-autistic adults quickly and reliably.

Does Camouflaging Cause Reduced Quality of Life? A Co-Twin Control Study

Camouflaging has been proposed to have a detrimental effect on quality of life, yet previous research has not accounted sufficiently for potential confounding by genetic and shared environmental factors. The current study utilized a co-twin control design providing stringent control for a range of confounders to investigate the hypothesis that camouflaging autistic traits has a negative impact on quality of life. The sample included 140 individual twins from 42 monozygotic (MZ) and 28 dizygotic (DZ) twin-pairs, enriched for participants with neurodevelopmental conditions including 22 autistic participants. All twins provided self-reports of camouflaging and quality of life. Autistic participants and specifically autistic females displayed increased camouflaging behaviors compared to non-autistic participants. Across the sample, higher levels of camouflaging were associated with reduced quality of life, surviving adjustment for confounding effects of autistic traits, ADHD, sex, and age. Within DZ- as well as MZ-pairs, which provide the highest level of control for unmeasured confounders, twins who camouflaged more reported lower quality of life compared to their co-twins, consistent with a causal influence of camouflaging on quality of life. Our results strengthen previous claims purporting camouflaging behaviors as a risk factor for reduced quality of life.

An Examination of Perceived Stress and Emotion Regulation Challenges as Mediators of Associations Between Camouflaging and Internalizing Symptomatology

Background

Camouflaging involves the masking of autism traits, potentially creating an outer impression of "non-autisticness." Although associations of camouflaging with anxiety and depression in autistic adults are widely reported, factors that mediate these associations are unclear. We examined two potential mediators of the association between camouflaging and anxiety/depression: perceived stress and emotion regulation (ER) challenges.

Methods

Seven hundred eighty-seven autistic adults (18.2-78.2 years) recruited through Simons Powering Autism Research (SPARK) Research Match completed questionnaires, including the Camouflaging Autistic Traits Questionnaire (CAT-Q), and measures of autistic traits, depressive and anxious symptomatology, perceived stress, and ER challenges. Four moderated mediation models were tested. In all models the independent variable was CAT-Q total score, and the moderator variable was sex designated at birth. The dependent variable was depressive or anxious symptomatology, and the mediator variable was perceived stress or ER challenges.

Results

We found that more camouflaging, increased ER challenges, and higher levels of perceived stress were associated with greater depressive and anxious symptomatology. We also found that perceived stress and ER challenges significantly mediated the associations between camouflaging and both depression and anxiety. In the model with perceived stress and anxiety, sex moderated the mediation, with females showing a stronger mediation. There was no significant moderation in any of the other models.

Conclusion

We contextualize the findings within the broader literature on camouflaging as a response to stigma and other facets of minority stress. We discuss how the results of this study support the idea that the day-to-day stress of living in a neurotypical world, the cognitively demanding nature of camouflaging, and the constraints that camouflaging place on autistic people's behaviors in social contexts (e.g., contributing to suppressing ER strategies such as stimming), create a cycle that contributes to elevated rates of anxiety and depression in autistic people.

Sex Differences and Parent-Teacher Discrepancies in Reports of Autism Traits: Evidence for Camouflaging in a School Setting

The purpose of this study was to examine sex differences and informant discrepancies in parent- and teacher-reports of autism traits. Data were drawn from the Simons Simplex Collection to create a sex-matched sample of autistic youth (N = 388; 4-17 years). Included participants had both parent and teacher reports of autistic traits from the Social Responsiveness Scale (SRS). Within each sex group, parent and teacher raw SRS scores were compared. Scores within each informant group (parent/teacher) was assessed for sex differences. Predictors of parent-teacher discrepancies were examined. Despite no sex differences in parent-reported autistic traits, teachers reported males as having more autistic traits compared to females. Parents of females reported significantly more autistic traits than teachers across multiple domains. Being older and female were significant predictors of increased parent-teacher discrepancy for multiple domains. These results suggest discrepancies between the observed autistic traits for females at home and school and builds on the growing body of literature highlighting potential camouflaging across development in autistic youth: parent-teacher discrepancies may reflect ways that autistic females are overlooked by teachers due to conscious changes in behavior or gender-based expectations of female characteristics. Discussion of discrepancies on an individual basis may therefore alleviate potential long-term consequences of camouflaging.

Autistic adults' perspectives and experiences of diagnostic assessments that include play across the lifespan

LAY ABSTRACT

Play is often included in autism diagnostic assessments. These assessments tend to focus on negatives and how people who are not autistic interpret observable behaviours. It is important to take a neurodiversity-affirmative assessment approach. This involves focusing on what autistic people say and looking at strengths and needs. We wanted to find out how autistic adults experience diagnostic assessments that include play. We asked autistic and non-autistic people to help us design our study and interview questions. We then interviewed 22 autistic adults to find out what they think about the use of play in assessments. We used a qualitative method called interpretative phenomenological analysis to analyse the data. Autistic adults told us about the different ways play was included in their diagnostic assessments. For example, some completed a diagnostic tool called the Autism Diagnostic Observation Schedule. Autistic adults also talked about the importance of considering how autistic people are different to each other. For example, we found that play may not be useful for assessing women or girls who mask. This suggests that professionals should adopt a personalised approach to diagnostic assessments that use play catering to each person's needs. Our findings also suggested that professionals should assess strengths and differences as well as needs.

The relationship between camouflaging and mental health: Are there differences among subgroups in autistic adults?

LAY ABSTRACT

When autistic people use strategies to hide their autistic characteristics, we call this camouflaging. Autistic adults suggested that camouflaging can result in mental health difficulties. That is, people who report to camouflage also report mental health difficulties. However, since there are many differences between autistic people, this relationship may also differ between subgroups. Therefore, in this study we investigated whether camouflaging and mental health difficulties are related and whether this relationship is equal for all autistic adults. For this study, 352 autistic adults aged 30-84 years filled in the Dutch Camouflaging Autistic Traits Questionnaire to measure camouflaging and the Symptom Checklist-90 Revised to measure mental health difficulties. We found that camouflaging was moderately related to mental health difficulties. This means that people who report more camouflaging also report more mental health difficulties. When we looked closer, we found that this relationship was strong for only a small subgroup of autistic adults. In most other autistic adults, there was a small or no relationship between camouflaging and mental health difficulties. Therefore, it is important that clinicians are aware of camouflaging and its possible relationship with mental health difficulties, but that they do not generalize the negative consequences to everyone.

Measurement matters: A commentary on the state of the science on patient reported outcome measures (PROMs) in autism research

High quality science relies upon psychometrically valid and reliable measurement, yet very few Patient Reported Outcome Measures (PROMs) have been developed or thoroughly validated for use with autistic individuals. The present commentary summarizes the current state of autism PROM science, based on discussion at the Special Interest Group (SIG) at the 2022 International Society for Autism Research (INSAR) Annual Meeting and collective expertise of the authors. First, we identify current issues in autism PROM research including content and construct operationalization, informant-structure, measure accessibility, and measure validation and generalization. We then enumerate barriers to conducting and disseminating this research, such as a lack of guidance, concerns regarding funding and time, lack of accessible training and professionals with psychometric skills, difficulties collecting large representative samples, and challenges with dissemination. Lastly, we offer future priorities and resources to improve PROMs in autism research including a need to continue to evaluate and develop PROMs for autistic people using robust methods, to prioritize diverse and representative samples, to expand the breadth of psychometric properties and techniques, and to consider developing field specific guidelines. We remain extremely optimistic about the future directions of this area of autism research. This work is well positioned to have an immense, positive impact on our scientific understanding of autism and the everyday lives of autistic people and their families.

Is camouflaging unique for autism? A comparison of camouflaging between adults with autism and ADHD

Camouflaging (using (un)conscious strategies to appear as non-autistic) is thought to be an important reason for late autism diagnoses and mental health difficulties. However, it is unclear whether only autistic people camouflage or whether people with other neurodevelopmental or mental health conditions also use similar camouflaging strategies. Therefore, in this preregistered study (AsPredicted: #41811) study, we investigated if adults with attention-deficit/hyperactivity-disorder (ADHD) also camouflage. Adults aged 30-90 years filled in the Dutch Camouflaging Autistic Traits Questionnaire (CAT-Q-NL), the ADHD Self-Report (ADHD-SR) and the Autism Spectrum Quotient (AQ). We investigated differences in camouflaging between adults with ADHD, autism, and a comparison group in an age and sex-matched subsample (N = 105 per group). We explored if autism and ADHD traits explained camouflaging levels in adults with an autism and/or ADHD diagnosis (N = 477). Adults with ADHD scored higher on total camouflaging and assimilation subscale compared to the comparison group. However, adults with ADHD scored lower on total camouflaging, and subscales compensation and assimilation than autistic adults. Autism traits, but not ADHD traits, were a significant predictor of camouflaging, independent of diagnosis. Thus, camouflaging does not seem to be unique to autistic adults, since adults with ADHD also show camouflaging behavior, even though not as much as autistic adults. However, as the CAT-Q-NL specifically measures camouflaging of autistic traits it is important to develop more general measures of camouflaging, to compare camouflaging more reliably in people with different mental health conditions. Furthermore, focusing on camouflaging in adults with ADHD, including potential consequences for late diagnoses and mental health seems a promising future research avenue.

The dimensional structure of the Camouflaging Autistic Traits Questionnaire (CAT-Q) and predictors of camouflaging in a representative general population sample

OBJECTIVES

Some autistic people "camouflage" their differences by modeling neurotypical behaviors to survive in a neurotypical-dominant social world. It remains elusive whether camouflaging is unique to autism or if it entails similar experiences across human groups as part of ubiquitous impression management (IM). Here we examined camouflaging engagement and theoretical drivers in the general population, drawing on the transactional IM framework and contextualizing findings within both contemporary autism research and the past IM literature.

METHODS

A large representative U.S. general population sample (N = 972) completed this survey study. We combined exploratory item factor analysis and graph analysis to triangulate the dimensional structure of the Camouflaging Autistic Traits Questionnaire (CAT-Q) and examined its correspondence with prior autism-enriched psychometric findings. We then employed hierarchical regression and elastic-net regression to identify the predictors of camouflaging, including demographic (e.g., age, gender), neurodivergence (i.e., autistic and ADHD traits), socio-motivational, and cognitive factors.

RESULTS

We found a three-factor/dimensional structure of the CAT-Q in the general population, nearly identical to that found in previous autism-enriched samples. Significant socio-motivational predictors of camouflaging included greater social comparison, greater public self-consciousness, greater internalized social stigma, and greater social anxiety. These camouflaging drivers overlap with findings in recent autistic camouflaging studies and prior IM research.

CONCLUSIONS

The novel psychometric and socio-motivational evidence demonstrates camouflaging as a shared social coping experience across the general population, including autistic people. This continuity guides a clearer understanding of camouflaging and has key implications for autism scholars, clinicians, and the broader clinical intersecting with social psychology research. Future research areas are mapped to elucidate how camouflaging/IM manifests and functions within person-environment transactions across social-identity and clinical groups.

Social Knowledge & Performance in Autism: A Critical Review & Recommendations

Autistic social challenges have long been assumed to arise from a lack of social knowledge ("not knowing what to do"), which has undergirded theory and practice in assessment, treatment, and education. However, emerging evidence suggests these differences may be better accounted for by difficulties with social performance ("doing what they may know"). This distinction has important implications for research, practice, policy, and community support of autistic people. This review examines the theoretical and clinical implications and empirical status of the knowledge-performance distinction in autism. Current evidence suggests that social knowledge deficits are neither definitional nor reliably related to outcomes in autism. Prioritizing social knowledge, then, may produce unanticipated, problematic consequences in terms of accuracy of assessment, intervention effectiveness, and promotion of stigma. It may also yield unrealistic expectations around the value of knowledge for autistic people and their families, yielding important ethical considerations. Conversely, recent evidence highlights performance-related factors as being especially promising for better modeling and addressing social challenges in autism. Prioritizing performance, then, may offer new directions for assessment, substantially different intervention opportunities, and novel methods of inclusion and affirmation. This review touches upon each of these domains and implications, integrates these developments with broader models of social competence in youth, and provides direction for future research and practice regarding social competence in autism.

Sex Differences on the ADOS-2

The sex difference in the prevalence of autism spectrum disorder (ASD) may be magnified by sex differences on diagnostic measures. The current study compared autistic males and females on items on the gold-standard diagnostic measure, the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2). In a sample of 8-to-17-year old autistic individuals from research (n = 229) and clinical settings (n = 238), females were less likely to show atypicalities on most items related to social-communication behaviors and on total and subscale scores. When controlling for overall intensity of symptomatology, no sex differences survived statistical corrections. Diagnostic criteria and/or gold-standard assessments may be less sensitive to female presentations of ASD and/or autistic females may exhibit fewer or less intense behaviors characteristic of ASD.

A comparison of methods for measuring camouflaging in autism

Interest in social camouflaging has led to a multiplicity of measurement methods of uncertain validity. This two-part investigation first used a systematic review ("Study 1") to identify and appraise methods used to quantify camouflaging of autistic traits, using the Consensus-based Standards for the Selection of Health Status Measurement Instruments checklist. A total of 16 distinct measurement tools were identified; all are in the preliminary phases of psychometric evaluation. The systematic review highlighted: (1) the need for parent-report tools which specifically measure camouflaging; and (2) a lack of studies looking at associations between different methods of camouflaging, which limits understanding of their validity. "Study 2" aimed to begin to address these gaps in knowledge. We created a parent-report version of the Camouflaging Autistic Traits Questionnaire (CAT-Q) and evaluated its concurrent validity in autistic young people by examining associations with the self-report CAT-Q and a discrepancy measure. Discriminant validity was investigated by comparing all three methods of measuring camouflaging to a measure of social skills, to test whether they assess a construct distinct from social ability. The self- and parent-report CAT-Q were significantly related (r = 0.47, 95% CI = 0.24-0.65), and were related weakly (r = 0.20, 95% CI = -0.06 to 0.43) and strongly (r = 0.46, 95% CI = 0.23-0.64), respectively, to the discrepancy approach. No measure was associated with social skills. Improving the psychometric properties of these methods, and introducing a novel parent-report measure, may help selection of appropriate methods in future research and integration into clinical practice.

A molecular framework for autistic experiences: Mitochondrial allostatic load as a mediator between autism and psychopathology

Molecular autism research is evolving toward a biopsychosocial framework that is more informed by autistic experiences. In this context, research aims are moving away from correcting external autistic behaviors and toward alleviating internal distress. Autism Spectrum Conditions (ASCs) are associated with high rates of depression, suicidality and other comorbid psychopathologies, but this relationship is poorly understood. Here, we integrate emerging characterizations of internal autistic experiences within a molecular framework to yield insight into the prevalence of psychopathology in ASC. We demonstrate that descriptions of social camouflaging and autistic burnout resonate closely with the accepted definitions for early life stress (ELS) and chronic adolescent stress (CAS). We propose that social camouflaging could be considered a distinct form of CAS that contributes to allostatic overload, culminating in a pathophysiological state that is experienced as autistic burnout. Autistic burnout is thought to contribute to psychopathology via psychological and physiological mechanisms, but these remain largely unexplored by molecular researchers. Building on converging fields in molecular neuroscience, we discuss the substantial evidence implicating mitochondrial dysfunction in ASC to propose a novel role for mitochondrial allostatic load in the relationship between autism and psychopathology. An interplay between mitochondrial, neuroimmune and neuroendocrine signaling is increasingly implicated in stress-related psychopathologies, and these molecular players are also associated with neurodevelopmental, neurophysiological and neurochemical aspects of ASC. Together, this suggests an increased exposure and underlying molecular susceptibility to ELS that increases the risk of psychopathology in ASC. This article describes an integrative framework shaped by autistic experiences that highlights novel avenues for molecular research into mechanisms that directly affect the quality of life and wellbeing of autistic individuals. Moreover, this framework emphasizes the need for increased access to diagnoses, accommodations, and resources to improve mental health outcomes in autism.

The changing faces of autism: The fluctuating international diagnostic criteria and the resulting inclusion and exclusion-A Norwegian perspective

The common understanding of autism spectrum disorders (ASD) has gone through a number of permutations since the first description in 1943. Throughout these shifting understandings, there have been a number of behaviors and diagnostic criteria associated with the condition, many of which are missing in the most recent classifications. The rates of diagnoses of autism have increased greatly. However, there is no reason to think there has been any change in occurrence over the last 70 years, suggesting rather an increase in our knowledge and awareness. Autism has been the subject of several misapprehensions and misrepresentations throughout history. This might be due to heterogeneity of the cases. In addition, the diagnosing of autism spectrum disorders is mainly based on observation and behavioral interpretation, and thus dependent on subjective perceptions of the clinicians themselves. This current scoping review article intends to provide a view on the evolution of the concept of autism and the current stance within Norwegian scholarship, and how it is shaped by international discourses and cultural diversities Such changing concepts especially impacts people with the diagnosis, as it can affect their access to social services, as well as their self-identification as people with ASD.

Towards equitable diagnoses for autism and attention-deficit/hyperactivity disorder across sexes and genders

PURPOSE OF REVIEW

Sex/gender-related factors contribute to contextual issues influencing the recognition of autism and attention-deficit/hyperactivity disorder (ADHD), and modulate how neurodevelopmental characteristics are manifested. This review summarizes the empirical literature to provide directions for improving clinical diagnostic practices.

RECENT FINDINGS

Timing of autism and/or ADHD diagnosis, particularly in girls/women, is related to the individual's developmental characteristics and co-occurring diagnoses, and expectancy, alongside gender stereotype biases, of referral sources and clinicians. This is further compounded by sex and gender modulations of behavioural presentations. The emerging 'female autism phenotype' concept may serve as a helpful illustration of nuanced autism phenotypes, but should not be viewed as essential features of autism in a particular sex or gender. These nuanced phenotypes that can present across sexes and genders include heightened attention to socially salient stimuli, friendship and social groups, richness in language expression, and more reciprocal behaviours. The nuanced female-predominant ADHD phenotypes are characterized by subtle expressions in hyperactivity-impulsivity (e.g., hyper-verbal behaviours). Optimizing neurodevelopmental diagnoses across sexes and genders also requires an understanding of sex-related and gender-related variations in developmental trajectories, including compensation/masking efforts, and the influences of co-occurring conditions on clinical presentations.

SUMMARY

Equitable diagnoses across sexes and genders for autism and ADHD require understanding of the nuanced presentations and the Gestalt clinical-developmental profiles, and addressing contextual biases that influence diagnostic practices.

Self-reported camouflaging behaviours used by autistic adults during everyday social interactions

LAY ABSTRACT

Camouflaging can be thought of as the process through which autistic people modify their natural social behaviours to adapt to, cope within or influence the largely neurotypical (non-autistic) social world. Many autistic people experience negative reactions to their natural or intuitive social behaviours when interacting with non-autistic people. Over time, in response to these negative reactions, autistic people's social behaviour often changes. We refer to autistic people's changed behaviours as 'camouflaging behaviours'. Research exploring camouflaging behaviours is still at an early stage. This study investigated camouflaging behaviours used by autistic adults in everyday social interactions using a research method that was new to the field of autism. Specifically, 17 autistic adults were filmed taking part in a common everyday social situation - a conversation with a stranger. With the help of the video of this conversation, they then showed and described their camouflaging behaviours to a researcher. These autistic people identified and described a total of 38 different camouflaging behaviours. The detailed and specific information provided by autistic adults about camouflaging behaviours generated important new insights into the ways in which autistic people adapt to, cope within and influence the neurotypical (non-autistic) social world.

Commentary: The construct validity of 'camouflaging' in autism: psychometric considerations and recommendations for future research - reflection on Lai et al. (2020)

Research on the construct of 'camouflaging' in autism and its sociodemographic/clinical correlates has far outpaced the work being done to establish the construct validity of camouflaging and its distinction from other similar constructs. The imprecision with which camouflaging is defined and measured has serious implications for future research on this topic, and unless additional effort is made to produce reliable and valid measurements of this construct, researchers will not be able to meaningfully assess important questions such as whether the effort of camouflaging one's behavior contributes to increased mental health difficulties. By reviewing the psychometric strengths and weaknesses of various operationalizations of camouflaging, this commentary highlights a pressing need for further measure validation in this area. Specific methodological guidance is provided for researchers interested in rigorously testing the validity of putative camouflaging measures.

Childhood diagnoses in individuals identified as autistics in adulthood

Background

Autism is a developmental condition, where symptoms are expected to occur in childhood, but a significant number of individuals are diagnosed with autism for the first time in adulthood. Here, we examine diagnoses given in childhood among individuals that are diagnosed with autism in adulthood, to investigate whether the late autism diagnosis might be explained by misdiagnosis in childhood or diagnostic overshadowing.

Methods

Through the Danish National Patient Registry, we identified individuals diagnosed with autism in adulthood (N = 2199), as well as a control sample with no records of an autism diagnosis (N = 460,798) and calculated how many had received different psychiatric or neurological diagnoses in childhood.

Results

We found that most childhood diagnoses were overrepresented in those with an adult autism diagnosis, and attention-deficit hyperactivity disorder, affective disorders, anxiety, and stress disorders were the most prevalent childhood conditions in this group. However, 69% of males and 61% of females with adult autism diagnoses were not found to have received any of the investigated diagnoses before 18 years of age, and most childhood diagnoses were given after the age of 12.

Limitations

Milder to moderate cases of psychiatric conditions that have been solely treated by family physicians or school psychologists may not be fully included in our dataset. The study is based on data from the Danish health care system, and further research is needed to assess whether the findings can be generalized to other countries.

Conclusion

A majority of those with an adult autism diagnosis had no records of having received any of the investigated diagnoses in childhood. In these cases, the late autism diagnosis is therefore unlikely to be explained by either misdiagnosis or overshadowing. This result is at odds with the prevailing notion that autistic symptoms tend to diminish with age. Therefore, further research is warranted to examine how and if early signs of autism may have manifested among these individuals, and how similar they are to autistic people diagnosed earlier in their development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13229-021-00478-y.

A Systematic Review of Passing as Non-autistic in Autism Spectrum Disorder

While long described in anecdotal accounts of the lived experiences of autistic individuals, the phenomenon of behaving in ways that appear inconsistent with the presence of autism (or passing as non-autistic; PAN) has recently seen a dramatic increase in scrutiny in the published scientific literature. Increased research attention has coincided with a proliferation of methods, definitions, measures, and population assumptions associated with PAN. To date, however, no review has sought to systematically identify and synthesize the literature on PAN. This systematic review reflects the state of the PAN literature as of May 2020. Ninety articles were screened, 66 were identified for evaluation, and 46 met inclusion criteria and were reliably coded for study characteristics and participant characteristics. Results reveal that the PAN literature includes a relatively even mix of qualitative, quantitative, and mixed-method studies, and that a variety of terms are used for PAN (with masking and camouflage being the most frequent). Sample sizes varied widely (from one to 832 participants), with 63.06% of participants being categorized as autistic. Nearly all studies reported methods for confirming autism diagnoses, with community and clinical diagnoses being most common. The majority of studies reported participant gender, with slightly more females included than males on average, but fewer than half of all studies compared PAN across genders. Nearly all studies reported participant age, demonstrating a wide range of 2 to 79 years, with a mean age of 23.85. Conversely, only 23.91% of studies provided participant race or ethnicity data. Nearly all studies formally or informally excluded participants with intellectual disability. Finally, measures of internalizing symptoms, which are often thought to be linked to PAN, were reported in only 17.4% of studies. Implications for gaps in understanding of PAN and future directions for the field are discussed.