Autism Spectrum Disorder Adults Research Articles

Protracted dendritic growth in the typically developing human amygdala and increased spine density in young ASD brains.

The amygdala is a medial temporal lobe structure implicated in social and emotional regulation. In typical development (TD), the amygdala continues to increase volumetrically throughout childhood and into adulthood, while other brain structures are stable or decreasing in volume. In autism spectrum disorder (ASD), the amygdala undergoes rapid early growth, making it volumetrically larger in children with ASD compared to TD children. Here we explore: (a) if dendritic arborization in the amygdala follows the pattern of protracted growth in TD and early overgrowth in ASD and (b), if spine density in the amygdala in ASD cases differs from TD from youth to adulthood. The amygdala from 32 postmortem human brains (7-46 years of age) were stained using a Golgi-Kopsch impregnation. Ten principal neurons per case were selected in the lateral nucleus and traced using Neurolucida software in their entirety. We found that both ASD and TD individuals show a similar pattern of increasing dendritic length with age well into adulthood. However, spine density is (a) greater in young ASD cases compared to age-matched TD controls (<18 years old) and (b) decreases in the amygdala as people with ASD age into adulthood, a phenomenon not found in TD. Therefore, by adulthood, there is no observable difference in spine density in the amygdala between ASD and TD age-matched adults (≥18 years old). Our findings highlight the unique growth trajectory of the amygdala and suggest that spine density may contribute to aberrant development and function of the amygdala in children with ASD.

White Matter Microstructure of the Human Mirror Neuron System is Related to Symptom Severity in Adults with Autism.

Mirror neuron system (MNS) dysfunctions might underlie deficits in autism spectrum disorders (ASD). Diffusion tensor imaging based probabilistic tractography was conducted in 15 adult ASD patients and 13 matched, healthy controls. Fractional anisotropy (FA) was quantified to assess group differences in tract-related white matter microstructure of both the classical MNS route (mediating "emulation") and the alternative temporo-frontal route (mediating "mimicry"). Multiple linear regression was used to investigate structure-function relationships between MNS connections and ASD symptom severity. There were no significant group differences in tract-related FA indicating an intact classical MNS in ASD. Direct temporo-frontal connections could not be reconstructed challengeing the concept of multiple routes for imitation. Tract-related FA of right-hemispheric parieto-frontal connections was negatively related to autism symptom severity.

Investigating Sex Bias in the AQ-10: A Replication Study.

There are concerns that females with autism spectrum disorders (ASD) may be underidentified because of factors such as better camouflaging and poorer recognition of the signs of ASD in females. One stage at which females may be underidentified is during screening. In this study, we, therefore, evaluated whether the autism spectrum quotient (AQ-10), a brief recommended screening instrument for ASD in adults suspected of having ASD, showed any evidence of underestimating symptoms in females. Our results broadly replicate those of an earlier study in finding no strong evidence that the AQ-10 is biased against females. However, to achieve better performance in females, we suggest that one item be replaced with an item measuring more "female" manifestations of ASD.

Group cognitive behaviour therapy (CBT) for social interaction anxiety in adults with autism spectrum disorders (ASD)

BackgroundGroup social skills interventions (SSI) are partially effective for addressing the communication and social interaction impairments experienced by individuals with autism spectrum disorders (ASD). Social anxiety has been found to be a moderating mechanism for SSI in young people with ASD. Comparatively few studies have investigated the effectiveness of SSI in the adult ASD population, and none so far have investigated group approaches incorporating SSI and anxiety management techniques. MethodThe present study describes the design and evaluation of a non-randomised single-arm, 11 week group interaction anxiety and social skills intervention, piloted on three occasions during routine clinical practice at an adult ASD service. The intervention was informed by a cognitive behaviour therapy (CBT) framework. Eighteen cognitively-able adult males with ASD attended. Outcome measures were completed pre- and post-intervention. ResultsSelf-reported social anxiety improved (p=0.01, d=0.65). Low mood, general anxiety and functioning did not change significantly (p>0.05, d<0.20). Qualitative feedback indicated that participants found the intervention to be acceptable and useful for improving social knowledge and coping strategies, and reducing avoidance behaviours. Attrition was low (n=2). ConclusionsThese results suggest that integrating SSI and anxiety management techniques in a group format is acceptable to adults with ASD, and can reduce symptoms of social anxiety. Whether SSI enhance social skills in adults requires further investigation. In clinical practice, consideration should be given to augmenting SSI with CBT techniques designed to target concurrent symptoms of social anxiety.

Structural learning difficulties implicate altered hippocampal functioning in adults with autism spectrum disorder.

Structural learning is fundamental to the formation of cognitive maps that are necessary for learning, memory, and spatial navigation. It also enables successful navigation of the social world, which is something that individuals with autism spectrum disorder (ASD) find particularly difficult. To master these situations, a person needs to bind pieces of information to one another and to consider the context in which experiences happen. Such binding is a capacity of the hippocampus. Although altered hippocampal function has for long been suspected to play a role in the etiology of ASD, the relevant evidence has remained inconclusive because few behavioral tests that are known to specifically necessitate preserved hippocampal function have been employed in studies of ASD. To address this gap in the literature, a total sample of 57 pairs of age and ability matched ASD and comparison participants was divided into 3 subsamples who were asked either to complete structural learning, or 1 of 2 configural learning control tasks (biconditional discrimination and transverse patterning) drawn from animal research. As predicted, ASD adults demonstrated specific difficulty with structural learning but not with other forms of configural learning. These differences were not attributable to decreased attentional shifting or increased perseveration, which would have indicated atypical frontal modulation of hippocampal processes. Instead, the observations implicate atypical hippocampal functioning as the source of structural learning difficulties in ASD. The data suggest that disturbances in domain-general cognitive processes such as structural learning, caused by altered hippocampal function, play a critical role in the etiology of ASD. (PsycINFO Database Record

Brainstem Auditory Evoked Potentials for diagnosing Autism Spectrum Disorder, ADHD and Schizophrenia Spectrum Disorders in adults. A blinded study

The aim of the present study was to examine the clinical utility of complex auditory brainstem response (c-ABR) and investigate if c-ABR is helpful in the diagnostic procedure. Thirty-one adult psychiatric patients, thoroughly diagnosed with autism spectrum disorder (ASD) (n=16), ADHD (n=8), or schizophrenia spectrum disorder (SSD) (n=7) and 15 healthy controls (HC), were blindly assessed with SensoDetect BERA. This c-ABR correctly identified psychiatric diagnoses in 4 patients (13%) and provided partially correct diagnoses in 11 more patients. Of the 15 HC, 6 were misclassified as psychiatric patients. The Cohen´s kappa coefficient (κ) was substantial for HC (κ=0.67), fair for SSD (κ=0.37), slight for ADHD (κ=0.09) and without agreement in ASD (κ=−0.03). In conclusion, we found the c-ABR method unhelpful and unreliable as a tool in clinical diagnostics.

Pathological game use in adults with and without Autism Spectrum Disorder.

This study tested whether adults with autism spectrum disorder (ASD) are at higher risk for pathological game use than typically developing (TD) adults. Participants included 119 adults with and without ASD. Participants completed measures assessing daily hours of video game use, percent of free time spent playing video games, and symptoms of pathological game use. The results indicated that adults with ASD endorsed more symptoms of video game pathology than did TD adults. This relationship was strong, enjoying 300,000-to-1 odds in Bayesian model comparison. Results also showed that adults with ASD spent more daily hours playing video games and spent a higher percent of their free time playing video games than did TD adults. Even after adjustment for these differences in daily video game hours and proportion of free time spent on games, model comparisons found evidence for a difference in game pathology scores associated with ASD status. Additionally, escapism motives for playing video games was associated with game pathology scores in both ASD and TD adults, replicating and extending a previous report. In conclusion, the risk for pathological game use appears larger in adults with ASD compared with TD adults. These findings point to pathological game use as a potentially important focus of clinical attention in adults with ASD.

A Mixed Methods Study of Barriers to Formal Diagnosis of Autism Spectrum Disorder in Adults.

Delayed diagnosis of autism spectrum disorder (ASD) into adulthood is common, and self-diagnosis is a growing phenomenon. This mixed methods study aimed to explore barriers to formal diagnosis of ASD in adults. In a qualitative strand, secondary analysis of data on the experiences of 114 individuals who were self-diagnosed or formally diagnosed with ASD in adulthood was used to identify barriers. In a quantitative strand, 665 individuals who were self-diagnosed or formally diagnosed in adulthood were surveyed online to examine incidence and severity of barriers. Fear of not being believed by professionals was identified as the most frequently occurring and most severe barrier. Professionals must strategize to build trust with individuals with ASD, particularly when examining the accuracy of self-diagnosis.

Autism: Too eager to learn? Event related potential findings of increased dependency on intentional learning in a serial reaction time task

It has been suggested that people with autism spectrum disorder (ASD) have an increased tendency to use explicit (or intentional) learning strategies. This altered learning may play a role in the development of the social communication difficulties characterizing ASD. In the current study, we investigated incidental and intentional sequence learning using a Serial Reaction Time (SRT) task in an adult ASD population. Response times and event related potentials (ERP) components (N2b and P3) were assessed as indicators of learning and knowledge. Findings showed that behaviorally, sequence learning and ensuing explicit knowledge were similar in ASD and typically developing (TD) controls. However, ERP findings showed that learning in the TD group was characterized by an enhanced N2b, while learning in the ASD group was characterized by an enhanced P3. These findings suggest that learning in the TD group might be more incidental in nature, whereas learning in the ASD group is more intentional or effortful. Increased intentional learning might serve as a strategy for individuals with ASD to control an overwhelming environment. Although this led to similar behavioral performances on the SRT task, it is very plausible that this intentional learning has adverse effects in more complex social situations, and hence contributes to the social impairments found in ASD. Autism Res 2017, 10: 1533-1543. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Using Time Perception to Explore Implicit Sensitivity to Emotional Stimuli in Autism Spectrum Disorder

Establishing whether implicit responses to emotional cues are intact in autism spectrum disorder (ASD) is fundamental to ascertaining why their emotional understanding is compromised. We used a temporal bisection task to assess for responsiveness to face and wildlife images that varied in emotional salience. There were no significant differences between an adult ASD and comparison group, with both showing implicit overestimation of emotional stimuli. Further, there was no correlation between overestimation of emotional stimuli and autistic traits in undergraduate students. These data do not suggest a fundamental insensitivity to the arousing content of emotional images in ASD, or in individuals with a high degree of autistic traits. The findings have implications for understanding how emotional stimuli are processed in ASD.

A new test of advanced theory of mind: The "Strange Stories Film Task" captures social processing differences in adults with autism spectrum disorders.

Real-life social processing abilities of adults with autism spectrum disorders (ASD) can be hard to capture in lab-based experimental tasks. A novel measure of social cognition, the "Strange Stories Film task' (SSFt), was designed to overcome limitations of available measures in the field. Brief films were made based on the scenarios from the Strange Stories task (Happé) and designed to capture the subtle social-cognitive difficulties observed in ASD adults. Twenty neurotypical adults were recruited to pilot the new measure. A final test set was produced and administered to a group of 20 adults with ASD and 20 matched controls, alongside established social cognition tasks and questionnaire measures of empathy, alexithymia and ASD traits. The SSFt was more effective than existing measures at differentiating the ASD group from the control group. In the ASD group, the SSFt was associated with the Strange Stories task. The SSFt is a potentially useful tool to identify social cognitive dis/abilities in ASD, with preliminary evidence of adequate convergent validity. Future research directions are discussed. Autism Res 2017. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. Autism Res 2017, 10: 1120-1132. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Altered neuroplasticity of prefrontal cortex in adult autism spectrum disorder

Introduction: Stimulation-induced plastic changes in human prefrontal region have not been sufficiently elucidated due to lack of reliable biomarkers like motor evoked potentials (MEP). The study was aimed to establish reliable biomarkers of TMS-evoked potentials (TEP), which could evaluate the neuroplasticity in the heteromodal association cortices.

Quantitative Sensory Testing in adults with Autism Spectrum Disorders.

Altered sensory perception has been found in patients with autism spectrum disorders (ASD) and might be related to aberrant sensory perception thresholds. We used the well-established, standardized Quantitative sensory testing (QST) protocol of the German Research Network on Neuropathic Pain to investigate 13 somatosensory parameters including thermal and tactile detection and pain thresholds in 13 ASD adults and 13 matched healthy controls with normal IQ values. There were no group differences between somatosensory detection and pain thresholds. Two ASD patients showed paradoxical heat sensations and another two ASD subjects presented dynamic mechanical allodynia; somatosensory features that were absent in controls. These findings suggest that central mechanisms during complex stimulus integration rather than peripheral dysfunctions probably determine somatosensory alterations in ASD.

Enhanced Fine-Form Perception Does Not Contribute to Gestalt Face Perception in Autism Spectrum Disorder.

Individuals with autism spectrum disorder (ASD) show superior performance in processing fine detail, but often exhibit impaired gestalt face perception. The ventral visual stream from the primary visual cortex (V1) to the fusiform gyrus (V4) plays an important role in form (including faces) and color perception. The aim of this study was to investigate how the ventral stream is functionally altered in ASD. Visual evoked potentials were recorded in high-functioning ASD adults (n = 14) and typically developing (TD) adults (n = 14). We used three types of visual stimuli as follows: isoluminant chromatic (red/green, RG) gratings, high-contrast achromatic (black/white, BW) gratings with high spatial frequency (HSF, 5.3 cycles/degree), and face (neutral, happy, and angry faces) stimuli. Compared with TD controls, ASD adults exhibited longer N1 latency for RG, shorter N1 latency for BW, and shorter P1 latency, but prolonged N170 latency, for face stimuli. Moreover, a greater difference in latency between P1 and N170, or between N1 for BW and N170 (i.e., the prolongation of cortico-cortical conduction time between V1 and V4) was observed in ASD adults. These findings indicate that ASD adults have enhanced fine-form (local HSF) processing, but impaired color processing at V1. In addition, they exhibit impaired gestalt face processing due to deficits in integration of multiple local HSF facial information at V4. Thus, altered ventral stream function may contribute to abnormal social processing in ASD.

Cognitive Features of High-Functioning Adults with Autism and Schizophrenia Spectrum Disorders

Autism Spectrum Disorder (ASD) and schizophrenia share common features in terms of pathophysiology and clinical appearance. Cognitive deficits are also present in both disorders. However, ASD and schizophrenia are heterogeneous syndromes, and few studies have addressed patients with these disorders who have above average educational attainment. In this study, we assessed the cognitive functions of a group of adult ASD patients with adequate mental development and verbal communication skills (High Functioning Autism, HFA) and compared them with a group of Schizophrenia patients matched for level of education. Three groups of patients and controls [(HFA, n= 32), Schizophrenia (n= 17), Controls (n= 23)], all with at least a high school education, were assessed with the Wechsler Adult Intelligence Scale (WAIS), Wisconsin Card Sorting Test (WCST), and Rey Auditory Verbal Learning Test (RAVLT). For the assessment of HFA, scores on the Autism Spectrum Disorders in Adults Screening Questionnaire were taken into consideration. Clinical diagnoses were based on DSM-IV TR and DSM-5 criteria. High Functioning Autism and Schizophrenia groups performed similarly in all subtests except for WAIS Comprehension and Digit Symbol, WCST Perseveration, and RAVLT Learning. Comprehension abilities of educated adults with HFA could be higher than average in situations that do not involve social interaction. Tendency to perseveration in the presence of adequate concept formation ability may reflect the clinical symptoms of rigidity and repetitive behavior. In patients with higher levels of functioning and education, their diagnosis appears to be weakly associated with cognitive functioning. The potential roles of other variables, such as environmental factors, during development deserve further exploration in future studies.

Connections between Autism Spectrum Disorders (ASD) and Meares-Meares-Irlen Syndrome

Aim: With this case study, we hypothesize that identical concomitant symptoms exist between ASDs and Meares-Irlen Syndrome, determined by the level of visual stress. Method: A questionnaire was given to subjectively identify the type and degree of symptoms associated with visual perception, and if these symptoms disrupted quality of life and learning process. This questionnaire was composed of questions on visual symptoms such as: symptoms linked to near and far visual distortion, binocular visual dysfunction and reading or writing errors experienced by the patient. Results: This patient experienced a significant reduction in visual stress symptoms when wearing color-tinted lenses (p <.0001). With respect to our hypothesis, it appeared that treating the Meares-Irlen Syndrome with the color-tinted lenses, (1) improved the patient’s analysis of visual signals, and (2) reduced sensory hypersensitivity. Conclusion: In this case study, it appeared that certain ASD deficits might have been caused by Meares-Irlen Syndrome, notably a change in the integration of sensory data. We wanted to highlight the lack of Meares-Irlen Syndrome screening, which occurs because of a general unawareness of the syndrome. It is important to find ways to reduce this unawareness by developing the skill sets of different professionals in terms of adult ASD evaluations and consultations, by offering a scientific and holistic approach toward ASD individuals and by not excluding the possibility of an underlying Meares-Irlen Syndrome.

Cortical interactions during the resolution of information processing demands in autism spectrum disorders

IntroductionOur flexible and adaptive interactions with the environment are guided by our individual representation of the physical world, estimated through sensation and evaluation of available information against prior knowledge. When linking sensory evidence with higher‐level expectations for action, the central nervous system (CNS) in typically developing (TD) individuals relies in part on distributed and interacting cortical regions to communicate neuronal signals flexibly across the brain. Increasing evidence suggests that the balance between levels of signal and noise during information processing may be disrupted in individuals with Autism Spectrum Disorders (ASD).MethodsParticipants with and without ASD performed a visuospatial interference task while undergoing functional Magnetic Resonance Imaging (fMRI). We empirically estimated parameters characterizing participants’ latencies and their subtle fluctuations (noise accumulation) over the 16‐min scan. We modeled hemodynamic activation and used seed‐based analyses of neural coupling to study dysfunction in interference‐specific connectivity in a subset of ASD participants who were nonparametrically matched to TD participants on age, male‐to‐female ratio, and magnitude of movement during the scan.ResultsStochastic patterns of response fluctuations reveal significantly higher noise‐to‐signal levels and a more random and noisy structure in ASD versus TD participants, and in particular ASD adults who have the greatest clinical autistic deficits. While individuals with ASD show an overall weaker modulation of interference‐specific functional connectivity relative to TD individuals, in particular between the seeds of Anterior Cingulate Cortex (ACC) and Inferior Parietal Sulcus (IPS) and the rest of the brain, we found that in ASD, higher uncertainty during the task is linked to increased interference‐specific coupling between bilateral anterior insula and prefrontal cortex.ConclusionsSubtle and informative differences in the structure of experiencing information exist between ASD and TD individuals. Our findings reveal in ASD an atypical capacity to apply previously perceived information in a manner optimal for adaptive functioning, plausibly revealing suboptimal message‐passing across the CNS.

The Effects of a Romantic Relationship Treatment Option for Adults With Autism Spectrum Disorder

Adults with mild autism spectrum disorder (ASD) face challenges in romantic relationships. Healthy romantic relationships yield physical and mental health benefits important to improved quality of life, yet many adults with ASD do not experience successful romantic relationships precluding them from possible benefits. This is the first study that explores the effects of group counseling, using the protocol Relationship Enhancement®, for 38 adult ASD participants in treatment as usual and a modified condition. Social skills, empathy, and social support were measured pre- and posttreatment. Results indicate improvements in social skills and empathy in both treatment conditions.

The Relationship Between Autistic Traits and Atypical Sensory Functioning in Neurotypical and ASD Adults: A Spectrum Approach.

Sensory processing atypicalities are a common feature in Autism Spectrum Disorders (ASD) and have previously been linked to a range of behaviours in individuals with ASD and atypical neurological development. More recently research has demonstrated a relationship between autistic traits in the neurotypical (NT) population and increased levels of atypical sensory behaviours. The aim of the present study is to extend previous research by examining specific patterns across aspects of autistic traits and sensory behaviours within both ASD and NT populations. The present study recruited 580 NT adults and 42 high-functioning ASD adults with a confirmed diagnosis to investigate the relationship between specific aspects of autistic traits and sensory processing using the subscales of the autism spectrum quotient (AQ) and adult/adolescent sensory profile (AASP). Results showed a significant relationship between all subscales except for attention to detail and imagination on the AQ and provided the first evidence that the strength and pattern of this relationship is identical between NT and ASD adults. These data also provided support for the broader autism phenotype, uncovering a clear progression of sensory atypicalities in line with an increase in autistic traits, regardless of diagnostic status, which has potential implications for the spectrum approach to ASD and how sensory behaviours across the whole of the neurotypical population are conceptualised.

Oral health status of children and young adults with autism spectrum disorders: systematic review and meta‐analysis

Individuals with special needs are often affected by oral disorders such as dental caries and periodontal disease. Current data regarding prevalence of these conditions in individuals with autism spectrum disorders (ASD) are controversial. To conduct a systematic review and meta-analysis to verify the prevalence of dental caries and periodontal disease in individuals with ASD, especially children and young adults. Searches were conducted through MEDLINE/PubMed, Web of Science, and Scopus databases in December 2015. Studies were included if fulfilled the following eligibility criteria: to evaluate the oral health status of individuals with ASD; to be an observational study; and to assess the prevalence of dental caries and/or periodontal disease. Meta-analyses were conducted considering prevalence of dental caries and periodontal disease in individuals as outcome. Search strategy identified 928 potentially relevant articles and seven of them were included in this review. All included studies reported dental caries prevalence, and the pooled prevalence was 60.6% (95% CI: 44.0-75.1). Moreover, only three studies showed prevalence of periodontal disease, resulting in pooled prevalence of 69.4% (95% CI: 47.6-85.0). Prevalence of dental caries and periodontal disease in children and young adults with ASD can be considered as high, pointing to the need for oral health policies focused on these individuals.