Decreased structural connectivity and resting-state brain activity in the lateral occipital cortex is associated with social communication deficits in boys with autism spectrum disorder.

Autism spectrum disorder (ASD) is a prevalent neurodevelopmental disorder characterized by atypical social communication and repetitive behaviors. In this study, we applied a multimodal approach to investigate brain structural connectivity, resting state activity, and surface area, as well as their associations with the core symptoms of ASD. Data from forty boys with ASD (mean age, 11.5 years; age range, 5.5-19.5) and forty boys with typical development (TD) (mean age, 12.3; age range, 5.8-19.7) were extracted from the Autism Brain Imaging Data Exchange II (ABIDE II) for data analysis. We found significantly decreased structural connectivity, resting state brain activity, and surface area at the occipital cortex in boys with ASD compared to boys with TD. In addition, we found that resting state brain activity and surface area in the lateral occipital cortex was negatively correlated with communication scores in boys with ASD. Our results suggest that decreased structural connectivity and resting-state brain activity in the occipital cortex may impair the integration of verbal and non-verbal communication cues in boys with ASD, thereby impacting their social development.

Selective impairments in components of affective prosody in neurologically impaired individuals.

The intent and feelings of the speaker are often conveyed less by what they say than by how they say it, in terms of the affective prosody - modulations in pitch, loudness, rate, and rhythm of the speech to convey emotion. Here we propose a cognitive architecture of the perceptual, cognitive, and motor processes underlying recognition and generation of affective prosody. We developed the architecture on the basis of the computational demands of the task, and obtained evidence for various components by identifying neurologically impaired patients with relatively specific deficits in one component. We report analysis of performance across tasks of recognizing and producing affective prosody by four patients (three with right hemisphere stroke and one with frontotemporal dementia). Their distinct patterns of performance across tasks and quality of their abnormal performance provides preliminary evidence that some of the components of the proposed architecture can be selectively impaired by focal brain damage.

Evaluating social (pragmatic) communication disorder.

BACKGROUND: Social (pragmatic) communication disorder (SPCD) is a new diagnosis introduced by DSM-5, characterised by problems with verbal and nonverbal social communication. It is currently unclear whether SPCD is a valid diagnostic category, because little is known about the characteristics of those who meet its criteria. We sought to identify and describe cases of SPCD, to contribute to debates about its validity. We investigated whether the symptoms of SPCD cluster together to form a coherent syndrome that is distinct from autism spectrum disorder (ASD) in terms of its core and associated features. METHODS: Participants were young people (N = 1,081, age range = 4-18 years) who had attended a specialist social communication disorders clinic for children with fluent language and normal-range intelligence. Standardised parent-report data were collected using the Developmental, Dimensional and Diagnostic Interview (3Di), Child Communication Checklist (CCC) and Strengths and Difficulties Questionnaire (SDQ). An algorithm was designed using 3Di and CCC items to implement DSM-5 SPCD criteria. RESULTS: Eighty-eight young people met our criteria for SPCD, with 801 meeting DSM-5 ASD criteria and the remaining 192 having neither SPCD nor ASD ('clinical comparison group'). The core symptoms of SPCD co-occurred to a moderate degree (average interitem correlation = .22). SPCD cases had autistic social difficulties that were intermediate between ASD and the clinical comparison group. SPCD was associated with high rates of nonautistic psychopathology, with 63.5% scoring in the abnormal range of the SDQ's Total Problems scale. CONCLUSIONS: We did not find evidence that SPCD is qualitatively distinct from ASD. Rather, it appears to lie on the borderlands of the autism spectrum, describing those with autistic traits that fall just below the threshold for an ASD diagnosis. SPCD may have clinical utility for identifying people with autistic traits that are insufficiently severe for ASD diagnosis, but who nevertheless require support.

Subdimensions of social-communication impairment in autism spectrum disorder.

BACKGROUND: More refined dimensions of social-communication impairment are needed to elucidate the clinical and biological boundaries of autism spectrum disorders (ASD) and other childhood onset psychiatric disorders associated with social difficulties, as well as to facilitate investigations in treatment and long-term outcomes of these disorders. METHODS: This study was intended to identify separable dimensions of clinician-observed social-communication impairments by examining scores on a widely used autism diagnostic instrument. Participants included verbally fluent children ages 3-13 years, who were given a clinical diagnosis of ASD (n = 120) or non-ASD (i.e. ADHD, language disorder, intellectual disability, mood or anxiety disorder; n = 118) following a comprehensive diagnostic assessment. Exploratory and confirmatory factor analysis examined the factor structure of algorithm items from the Autism Diagnostic Observation Schedule (ADOS), Module 3. RESULTS: Results indicated that a three-factor model consisting of repetitive behaviors and two separate social-communication behavior factors had superior fit compared to a two-factor model that included repetitive behaviors and one social-communication behavior factor. In the three-factor model, impairments in 'Basic Social-Communication' behaviors (e.g. eye contact, facial expressions, gestures) were separated from impairments in 'Interaction quality.' Confirmatory factor analysis in an independent sample of children in the Simons Simplex Collection (SSC) further supported the division of social-communication impairments into these two factors. Scores in Interaction Quality were significantly associated with nonverbal IQ and male sex in the ASD group, and with age in the non-ASD group, while scores in basic social communication were not significantly associated with any of these child characteristics in either diagnostic group. CONCLUSIONS: Efforts to conceptualize level, or severity, of social-communication impairment in children with neurodevelopmental disorders might be facilitated by separating the most basic (or proximal) social-communication impairments from those that could arise from a range of other phenotypic variables. Identification of social-communication subdimensions also highlights potential avenues for measuring different types of social-communication impairments for different purposes (e.g. for differential diagnosis vs. response to treatment).

Frontal and Temporal Structural Connectivity Is Associated with Social Communication Impairment Following Traumatic Brain Injury.

OBJECTIVES: Although it has been well documented that traumatic brain injury (TBI) can result in communication impairment, little work to date has examined the relationship between social communication skills and structural brain integrity in patients with TBI. The aim of the current study was to investigate the association between self- and other-perceived communication problems and white matter integrity in patients with mild to severe TBI. METHODS: Forty-four individuals (TBI=24) and people with whom they frequently communicate, as well as demographically matched normal healthy comparisons (NC) and their frequent communication partners, were administered, respectively, the La-Trobe Communication Questionnaire Self form (LCQ-SELF) and Other form (LCQ-OTHER). In addition, diffusion tensor imaging data were collected, and fractional anisotropy (FA) measures were extracted for each lobe in both hemispheres. RESULTS: Within the TBI group, but not within the NC group, participants who were perceived by their close others as having more communication problems had lower FA in the left frontal and temporal lobes (p<.01), but not in other brain regions. CONCLUSIONS: Frontotemporal white matter microstructural integrity is associated with social communication abilities in adults with TBI. This finding contributes to our understanding of the mechanisms leading to communication impairment following TBI and can inform the development of new neuromodulation therapies as well as diagnostic tools. (JINS, 2016, 22, 705-716).

Referring expressions and structural language abilities in children with specific language impairment: A pragmatic tolerance account.

Specific language impairment (SLI) has traditionally been characterized as a deficit of structural language (specifically grammar), with relative strengths in pragmatics. In this study, comprehensive assessment of production, comprehension, and metalinguistic judgment of referring expressions revealed that children with SLI have weaknesses in both structural and pragmatic language skills relative to age-matched peers. Correlational analyses highlight a relationship between their performance on the experimental tasks and their structural language ability. Despite their poor performance on the production and comprehension tasks, children with SLI were able to recognize pragmatically under-informative reference relative to other types of utterance, although they imposed a less severe penalty on such expressions than typically developing peers, a pattern that supports the pragmatic tolerance account. Our novel methodology (which probed structural abilities from both the speaker's and hearer's perspectives as well as metalinguistic and pragmatic skills in the same sample) challenges the assumption that pragmatic errors stem from deficits in social cognition and instead supports recent findings suggesting that when the impact of structural language is isolated, pragmatic deficits may be resolved.

Evidence of Pragmatic Impairments in Speech and Proverb Interpretation in Schizophrenia.

Schizophrenia has been suggested to involve linguistic pragmatic deficits. In this study, two aspects of pragmatic ability were assessed; comprehension and production. Drawing on relevance theory and Gricean implicatures to assess shared attention and interpretation in a linguistic context, discourse samples and proverb interpretation were transcribed from recorded interviews with patients with schizophrenia and control subjects. The productive aspect of implicatures was assessed by quantifying the use of 'connectors' in discourse. Receptive aspects were assessed by scoring interpretations of four common proverbs. Statistically significant effects were found: patients with schizophrenia used connectors less than controls as well as performing worse in proverb comprehension. Positive correlations between connectors and proverb interpretation in all subjects suggested an underlying pragmatic root for both productive and receptive aspects. The relative number of connectors (as a percentage of words used) provided a better index of pragmatic ability than total number because total output appeared to be influenced by additional factors such as IQ. Deficits were found in the use of connectors and in proverb interpretation even when controlling for verbal IQ, suggesting that pragmatic aspects of language are particularly vulnerable in schizophrenia compared with other verbal abilities.

Social neuroscience and theory of mind.

BACKGROUND: The role of theory of mind (ToM) in autism spectrum disorders and other communication impairments has been an active area of research in the last 30 years. Advances in neuroimaging in the last 10 years have led to the rise of the field of social neuroscience, which has markedly increased the understanding of the neurophysiological/neuroanatomical and neurochemical nature of ToM functioning and deficits in typically developing individuals and in children and adults with a variety of social and communication impairments. OBJECTIVE: The goal of this paper is to (a) describe the current concepts of ToM based on neuroscience research, and (b) present a framework for the dimensions of ToM that have been identified, which can be used to guide assessment and intervention for persons with deficits in ToM that affect social interactions. SUMMARY: This article presents neuroscience research that has documented the neurophysiological/neuroanatomical bases for cognitive and affective ToM and interpersonal and intrapersonal ToM as well as neurochemical and epigenetic influences on ToM. This information provides an important framework for assessing ToM deficits in persons with social and communication impairments and developing interventions that target the specific dimensions of ToM deficits.

Psychiatric Assessment of Social Impairment Across the Lifespan.

Although autism spectrum disorder (ASD) is the prototypical psychiatric disorder of social impairment, several if not most psychiatric disorders are characterized by prominent impairments in social functioning. A challenge in clinically assessing and describing social impairment is that it has been variably defined and can be difficult to measure. In this article we consider the psychiatric differential diagnosis of social impairment within the DSM-5 framework. We describe the features of social impairment in 13 DSM-5 disorders from a developmental perspective and highlight diagnostic factors that differentiate among the disorders, including the main features of social impairment, verbal communication, nonverbal communication, course of social impairment, social cognition, and key features of accompanying neuropsychiatric symptoms. We conclude by describing an approach for assessing social impairment across the lifespan.

Adaptation to different communicative contexts: an eye tracking study of autistic adults.

BACKGROUND: Learning through social observation (i.e., watching other people interact) lays the foundation for later social skills and social cognition. However, social situations are often complex, and humans are only capable of attending to one aspect of a scene at a time. How do people choose where to allocate their visual resources when viewing complex social scenarios? For typically developing (TD) individuals, faces are often given priority. Depending upon context, however, it may be more useful to attend to other aspects of the environment, such as hands, tools, or background objects. Previous studies reported reduced face looking in individuals with autism spectrum disorder (ASD), but modulation of visual attention in response to contextual differences (e.g., according to social richness, or the presence/absence of communicative behaviors between two people) has only briefly been explored. In this study, we used eye-tracking technology to test the extent to which ASD adults and TD adults use social context to guide their gaze behavior. METHODS: Fifty-five adults participated (28 with ASD). The location and duration of participants' gaze were recorded while they watched a series of naturalistic social videos. Half of the videos depicted two people engaging in non-verbal communication (rich social scenes) while playing with toys. The other half depicted two people playing with toys separately, not interacting with each other (lean social scenes). RESULTS: ASD and TD adults both increased their attention to faces in communicative contexts (rich social scenes) as compared to non-communicative contexts (lean social scenes). However, TD adults increased their attention to faces significantly more when watching two people communicate than did ASD adults, who increased their attention to a lesser degree. Further analysis revealed that ASD adults persisted in looking at hands and toys, even when observing two people communicate in a rich social scene. CONCLUSIONS: Diminished gaze to faces when observing two people communicating may lead to fewer opportunities for social learning and subsequent reductions in social knowledge. Naturalistic measures of contextual modulation could help identify areas of need for individuals learning about the social world and could become treatment targets to improve everyday social learning.

Autism spectrum disorder symptoms from ages 2 to 19 years: Implications for diagnosing adolescents and young adults.

This study explored change in social-communicative symptoms in 140 individuals with childhood autism spectrum disorder (ASD) diagnoses. Trajectories of caregiver-reported social-communicative symptoms were examined for three groups (verbal, delayed speech, minimally verbal) from ages 2 to 19 years. Groups showed comparable levels of social-communicative impairment at 2 years and significant decreases in overall symptom levels across the 17-year period (P < .001). Across three subdomains, main effects of time and language (P < .001) reflected patterns of overall improvement, although children with more impaired language tended to have more caregiver-reported symptoms relative to verbal peers. A significant time-by-language interaction (P < .001) reflected that trajectories of socioemotional reciprocity symptoms differed according to patterns of language development. In contrast, improvements in the nonverbal communication domain were seen across language groups, whereas deficits in the development and maintenance of relationships improved for only verbal children. Verbal adults showed significant reductions in the prevalence of kseveral symptoms exhibited during childhood. Improvements suggest that symptoms indicative of ASD in young children may no longer be diagnostic markers in adolescents and adults. Relative stability of several items suggests that impaired facial expression may be a core ASD symptom that warrants more systematic study across the lifespan. Research investigating the manifestation of ASD in older individuals is needed to foster development of appropriate assessment tools and interventions. Differential relationships to developmental factors within the broader social-communication domain underscores a need to focus on more narrowly defined symptom constructs when exploring links between pathophysiology and observable phenotypes. Autism Research 2019, 12: 89-99. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: In a sample of 140 participants with autism spectrum disorder (ASD) followed from 2 to 19 years old, this study found that overall social-communicative symptoms improve across childhood and adolescence. However, timing and amount of change varied for different symptom categories and participants with different language abilities. Findings suggest that some older adolescents and adults with ASD may not exhibit the same difficulties observed in young children with ASD. More research is needed to better understand the strengths and needs of young adults with ASD.

Social (Pragmatic) Communication Disorder: Another name for the Broad Autism Phenotype?

The Diagnostic and Statistical Manual of Mental Disorders' (5th ed.) Social (Pragmatic) Communication Disorder is meant to capture the social elements of communication dysfunction in children who do not meet autism spectrum disorder criteria. It is unclear whether Social (Pragmatic) Communication Disorder captures these elements without overlapping with Autism Spectrum Disorder or the Diagnostic and Statistical Manual of Mental Disorders' (5th ed.) Language Disorder. Standardized behavioral assessments administered during a family genetics study were used to evaluate the social communication impairment and the restricted interests and repetitive behaviors in persons with autism spectrum disorder, language impairment, or neither. Social communication impairment and restricted interests and repetitive behavior were significantly correlated in all family members regardless of affection status. Rates of social communication impairment and restricted interests and repetitive behavior were highest in individuals with autism spectrum disorder. One-third of family members with language impairment presented with at least mild/moderate levels of social communication impairment (36.6%) and restricted interests and repetitive behavior (43.3%). A subset of unaffected members also presented with mild/moderate levels of social communication impairment (parents = 10.1%, siblings 11.6%) and restricted interests and repetitive behavior (parents = 14.0%, siblings = 22.1%). The majority of child family members with mild/moderate levels of social communication impairment had similar restricted interest and repetitive behavior levels reflecting criteria representing the Broad Autism Phenotype. These data suggest that social pragmatic communication disorder does not capture the profiles of children who have both social communication impairment and restricted interests and repetitive behavior but are in need of clinical services.

Social communication following traumatic brain injury part I: State-of-the-art review of assessment tools.

PURPOSE: The primary aim of this paper was to identify and describe current social communication assessment tools for adults with traumatic brain injury. METHOD: We conducted a state-of-the-art review to identify and categorise the range of social communication assessment tools found in the assessment and treatment literature that revealed 42 measures that were coded according to characteristics related to assessment types, psychometrics, and implementation. RESULT: Of the 42 assessments, 64% evaluated social cognition and the remaining 36% evaluated communication. Coding of implementation categories revealed that only 18/42 (43%) measures were ecologically grounded and 23/42 (55%) were available to clinicians by purchase or in the public domain. Only three measures incorporated questions or an assessment of the examinee's priorities or concerns. CONCLUSION: A number of factors limit current social communication assessment. The lack of tools that objectively and reliably evaluate communication or social cognition in ecologically valid ways remains problematic. Of particular concern is the lack of prioritisation of the individual's communication values and needs. Recommendations include a call to focus research on the development of more contextual, standardised assessments, consider availability and feasibility when tools are being developed, and evaluate assessment processes as well as discrete tools.

Differentiating social preference and social anxiety phenotypes in fragile X syndrome using an eye gaze analysis: a pilot study.

BACKGROUND: Fragile X syndrome (FXS) is the leading inherited cause of autism spectrum disorder, but there remains debate regarding the clinical presentation of social deficits in FXS. The aim of this study was to compare individuals with FXS to typically developing controls (TDC) and individuals with idiopathic autism spectrum disorder (ASD) across two social eye tracking paradigms. METHODS: Individuals with FXS and age- and gender-matched TDC and individuals with idiopathic ASD completed emotional face and social preference eye tracking tasks to evaluate gaze aversion and social interest, respectively. Participants completed a battery of cognitive testing and caregiver-reported measures for neurobehavioral characterization. RESULTS: Individuals with FXS exhibited reduced eye and increased mouth gaze to emotional faces compared to TDC. Gaze aversive findings were found to correlate with measures of anxiety, social communication deficits, and behavioral problems. In the social interest task, while individuals with idiopathic ASD showed significantly less social preference, individuals with FXS displayed social preference similar to TDC. CONCLUSIONS: These findings suggest fragile X syndrome social deficits center on social anxiety without the prominent reduction in social interest associated with autism spectrum disorder. Specifically designed eye tracking techniques clarify the nature of social deficits in fragile X syndrome and may have applications to improve phenotyping and evaluate interventions targeting social functioning impairments.

Measuring child social communication across contexts: Similarities and differences across play and snack routines.

Improving measurement of outcomes in randomized controlled trials of early interventions for autism spectrum disorder (ASD) has been identified as a priority in the field. In addition, the importance of measurement across contexts has been indicated by researchers and community stakeholders alike [Lord et al., ; McConachie et al., ; Schreibman et al., ]. The Brief Observation of Social Communication Change (BOSCC; Grzadzinski et al., ), an observational rating scheme of brief play interactions, was developed to address a need for measures that are reliable, sensitive to change, and valid for use in research settings. The goal of this study was to examine the feasibility and utility of applying the BOSCC to a new context: a home snack routine. Results suggest that rating the BOSCC on home snack routines is feasible and psychometrically sound, and captures change in child social communication behaviors. However, the utility of the BOSCC for measuring restricted and repetitive behaviors (RRBs) is less clear. Nonetheless, differences in RRBs across play and snack lend support for the claim that measurement across contexts is essential. Application of the BOSCC across contexts may allow researchers to obtain a more accurate estimate of intervention response and help capture context-specific changes in social communication. It may also provide a method for researchers to evaluate the effect of context on child social communication more broadly. Autism Res 2019, 12: 636-644. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Improving measurement of outcomes in studies of early interventions for autism spectrum disorder (ASD) has been identified as a priority in the field. The importance of measurement across contexts has also been indicated by researchers and community stakeholders. The goal of this study was to determine whether an existing observational rating scheme, the Brief Observation of Social Communication Change (BOSCC), could be applied to a new activity: a home snack routine. Results suggest that rating the BOSCC on home snack routines is feasible and promising for capturing change over time. In addition, some child behaviors differed across play and snack, lending further support for the claim that measurement across activities is essential.

Pragmatic competence of children with autism spectrum disorder. Impact of theory of mind, verbal working memory, ADHD symptoms, and structural language.

The primary aim of this study is to increase the existing knowledge about the pragmatic skills of children with autism spectrum disorders (ASD). Specifically, the study has two objectives. The first is to provide a profile of characteristics based on The Children's Communication Checklist (CCC-2) pragmatics scales (inappropriate initiation, stereotyped language, use of context, nonverbal communication, and general pragmatics) and narrative task indicators. To this end, children with ASD will be compared to children with typical development (TD), controlling the effects of sex and structural language (speech, syntax, semantics, coherence). The second objective is to analyze whether theory of mind (ToM), verbal working memory, ADHD symptoms, and structural language can predict pragmatic competence in children with ASD without intellectual disability (ID). The results showed worse performance in the group with ASD on the majority of the pragmatic aspects evaluated. In addition, the application of ToM skills and structural language were significant predictors of the pragmatic skills of the children with ASD. These findings reinforce the importance of focusing intervention programs on mentalist abilities through experiences in real social scenarios, along with strengthening structural language components.

Social communication following traumatic brain injury part 2: Identifying effective treatment ingredients.

PURPOSE: Social communication deficits are a severely debilitating aspect of traumatic brain injury (TBI), and there is strong clinical and research interest in how social communication interventions work for this population. Informed by a companion paper targeting assessment of social communication impairments post-TBI, this paper reviews relevant treatment theories and provides an inventory of social communication treatment components. METHOD: We completed a mapping review examining 17 articles from recent literature reviews and 4 updated articles from a literature search to identify treatment targets and ingredients using the Rehabilitation Treatment Specification System (RTSS). RESULT: Social communication interventions are primarily based on behavioural and cognitive treatment theories. Common social communication treatment targets include changing skilled behaviours and cognitive or affective representations. We offer a menu of therapeutic ingredients and treatment considerations which represent the current state of social communication interventions. CONCLUSION: By reviewing the social communication intervention literature through a theoretical lens, we identify which treatment targets are missing, which targets are being addressed, and which therapeutic ingredients (i.e. clinician activities) are recommended. A hypothetical case study is provided as a supplement to demonstrate how speech-language pathologists may integrate treatment theory, ingredients, and targets into clinical practice.

Structural neuroimaging correlates of social deficits are similar in autism spectrum disorder and attention-deficit/hyperactivity disorder: analysis from the POND Network.

Autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and obsessive-compulsive disorder (OCD) have been associated with difficulties recognizing and responding to social cues. Neuroimaging studies have begun to map the social brain; however, the specific neural substrates contributing to social deficits in neurodevelopmental disorders remain unclear. Three hundred and twelve children underwent structural magnetic resonance imaging of the brain (controls = 32, OCD = 44, ADHD = 77, ASD = 159; mean age = 11). Their social deficits were quantified on the Social Communication Questionnaire (SCQ) and the Reading the Mind in the Eyes Test (RMET). Multivariable regression models were used to examine the structural neuroimaging correlates of social deficits, with both a region of interest and a whole-brain vertex-wise approach. For the region of interest analysis, social brain regions were grouped into three networks: (1) lateral mentalization (e.g., temporal-parietal junction), (2) frontal cognitive (e.g., orbitofrontal cortex), and (3) subcortical affective (e.g., limbic system) regions. Overall, social communication deficits on the SCQ were associated with thinner cortices in the left lateral regions and the right insula, and decreased volume in the ventral striatum, across diagnostic groups (p = 0.006 to <0.0001). Smaller subcortical volumes were associated with more severe social deficits on the SCQ in ASD and ADHD, and less severe deficits in OCD. On the RMET, larger amygdala/hippocampal volumes were associated with fewer deficits across groups. Overall, patterns of associations were similar in ASD and ADHD, supporting a common underlying biology and the blurring of the diagnostic boundaries between these disorders.

Same or different? Theory of mind among children with and without disabilities.

Assessing theory of mind (ToM) with reliable and valid measures is important, as ToM plays a significant role in children's social and cognitive functioning. With this in mind, a thorough analysis of the Theory of Mind scale and the Faux Pas Recognition Test was conducted. Over 750 school-age (M age = 7.7) children with disabilities (mild intellectual disability, hearing impairment) and without disabilities took part in our study. The psychometric properties of measures in these groups of children were checked, using confirmatory item factor analysis, reliability, and validity analyses. Thanks to groups' invariance it was possible to compare mean results of children in the groups. Both measures showed well-fitted models with acceptable goodness of fit as well as scalar and strict invariance. An IRT analysis showed significant differences in the difficulty of the tasks in all groups, but the same order of passing tasks in comparison to other studies, conducted in Western countries, has been observed. Our results showed that the tasks were the easiest for children without disabilities, and most difficult for children with mild intellectual disability. We obtained significant and positive correlations between ToM and social skills and language abilities. The findings are discussed in relation to results from other studies in the field.

Developmental Changes Within the Genetic Architecture of Social Communication Behavior: A Multivariate Study of Genetic Variance in Unrelated Individuals.

BACKGROUND: Recent analyses of trait-disorder overlap suggest that psychiatric dimensions may relate to distinct sets of genes that exert maximum influence during different periods of development. This includes analyses of social communication difficulties that share, depending on their developmental stage, stronger genetic links with either autism spectrum disorder or schizophrenia. We developed a multivariate analysis framework in unrelated individuals to model directly the developmental profile of genetic influences contributing to complex traits, such as social communication difficulties, during an approximately 10-year period spanning childhood and adolescence. METHODS: Longitudinally assessed quantitative social communication problems (N ≤ 5551) were studied in participants from a United Kingdom birth cohort (Avon Longitudinal Study of Parents and Children; age range, 8-17 years). Using standardized measures, genetic architectures were investigated with novel multivariate genetic-relationship-matrix structural equation models incorporating whole-genome genotyping information. Analogous to twin research, genetic-relationship-matrix structural equation models included Cholesky decomposition, common pathway, and independent pathway models. RESULTS: A two-factor Cholesky decomposition model described the data best. One genetic factor was common to Social Communication Disorder Checklist measures across development; the other accounted for independent variation at 11 years and later, consistent with distinct developmental profiles in trait-disorder overlap. Importantly, genetic factors operating at 8 years explained only approximately 50% of genetic variation at 17 years. CONCLUSIONS: Using latent factor models, we identified developmental changes in the genetic architecture of social communication difficulties that enhance the understanding of autism spectrum disorder- and schizophrenia-related dimensions. More generally, genetic-relationship-matrix structural equation models present a framework for modeling shared genetic etiologies between phenotypes and can provide prior information with respect to patterns and continuity of trait-disorder overlap.