DSM-5 ASD moves forward into the past

Investigating the borders of autism spectrum disorder: lessons from the former diagnosis of pervasive developmental disorder not otherwise specified

Introduction

Autism Spectrum Disorder (ASD) diagnosis is relatively consensual in typical forms. The margins of the spectrum and their degree of extension, however, are controversial. This has far-reaching implications, which extend beyond theoretical considerations: first, peripheral forms of autism are more prevalent than central forms; second, we do not know how relevant typical-targeted recommendations are for atypical forms. In DSM-IV-TR, these margins of autism were studied within the category of Pervasive Developmental Disorder - Not Otherwise Specified (PDD-NOS). In spite of its low reliability, this former diagnosis was of particular interest to shed light on the gray area of margins. The aim of this systematic is therefore to investigate the clinical characteristics of PDD-NOS in comparison with Autistic Disorder.

Method

A stepwise systematic PRISMA literature review was conducted by searching PubMed and Web Of Science databases to select corresponding studies.

Results

The systematic review included 81 studies comprising 6,644 children with PDD-NOS. Cross-sectional and longitudinal studies comparing PDD-NOS and AD showed that PDD-NOS corresponds to milder form of autism with less impact and less associated disorder, with the exception of schizophrenia and mood disorder.

Discussion

Our review challenges initial views of PDD-NOS, and shows the clinical relevance of this diagnosis when dealing with the margins of autism, and the de facto diversity included in the spectrum. However, in view of the many limitations of PDD-NOS (low reliability, instability through time, low acceptability), we suggest taxonomic changes in DSM-5: we introduce a new category based on three main dimensions related to socialization impairment, emotional lability and psychotic symptoms.

Conclusion

Our review argues for a distinction between AD and PDD-NOS on clinical characteristics and thus highlights the need to study the margins of autism. While the limitations of the PDD-NOS category made it irrelevant to investigate these margins from a research perspective, we believe that a multidimensional approach for mental health professionals taping socialization, emotion lability and psychotic symptoms would be interesting. Our review therefore encourage future studies to test relevant criteria for a new category and possibly identify developmental trajectories, specific interventions and treatments.

Ophthalmologic diagnoses in youths with autism spectrum disorder: Prevalence and clinical correlates

Autism spectrum disorder (ASD) is associated with a high prevalence of visual dysfunction. This study aimed to investigate the rates of amblyopia, refractive errors, and strabismus, as well as their clinical correlates in ASD. This population-based matched-cohort study used data from the Taiwan National Health Insurance Research Database. A total of 3,551 youths with ASD and 35,510 non-autistic control participants matched by age and sex were included. All the participants were followed-up until they were 18 years old. The prevalence of amblyopia, refractive errors, and strabismus was compared between the ASD and control groups. Effect modifiers, including sex, ASD subgroup, and co-diagnosis of intelligence disability, were examined. Compared to the control group, youths with ASD had a significantly increased risk of amblyopia (adjusted odds ratio [aOR] = 1.75), anisometropia (aOR = 1.66), astigmatism (aOR = 1.51), hypermetropia (aOR = 2.08), exotropia (aOR = 2.86), and esotropia (aOR = 2.63), but a comparable likelihood of myopia according to age. Males with ASD had a significantly lower likelihood of exotropia, but a higher likelihood of myopia than females with ASD. The autism subgroup had a higher OR for hypermetropia, but a lower OR for myopia than the other ASD subgroups. ASD youths with intelligence disabilities demonstrated significantly higher ORs for amblyopia, hypermetropia, and all types of strabismus and lower OR for myopia than those without intelligence disabilities. In conclusion, the rates of amblyopia, refractive errors, and strabismus were higher in youths with ASD. Ocular abnormalities in youths with ASD require a comprehensive assessment and management.

Prototypical autism: New diagnostic criteria and asymmetrical bifurcation model

The current "autism spectrum" DSM 5 diagnostic criteria and autism standardized diagnostic instruments promote considerable heterogeneity or clinical indecision and may be detrimental to the advancement of fundamental research on autism mechanisms. To increase clinical specificity and reorient research towards core autistic presentations, we propose new diagnostic criteria for prototypical autism during the age of 2- to 5-years. We include autism within other non-dominant, familiarly aggregated phenomena sharing asymmetrical developmental bifurcations, such as twin pregnancy, left handedness, and breech presentation/delivery. Following this model, nature, trajectory, and positive/negative signs structure of autism would result from the polarized problem of whether or not language and information is processed in a socially biased manner. Prototypical autism would follow a canonical developmental trajectory by which a gradual decline in social bias in the processing of incoming information, overtly beginning at the end of the first year, bifurcates into a prototypical autistic presentation in the second half of the second year of life. This bifurcation event is followed by a plateau, in which these atypicalities show maximal stringency and distinctiveness, and then ultimately, in most cases, by partial normalization. During the plateau period, the orientation towards, and processing of, information is considerably modified, with an absence of bias for social information, contrasting with a high level of interest in complex, unbiased information, independently of its social or non-social nature. Integrating autism into asymmetrical developmental bifurcations would explain the absence of deleterious neurological and genetic markers and the presence of familial transmission in canonical autistic presentations.

A bibliometric analysis of global research status and trends in neuromodulation techniques in the treatment of autism spectrum disorder

BACKGROUND

Autism spectrum disorder (ASD) is a neurodevelopmental disease which has risen to become the main cause of childhood disability, placing a heavy burden on families and society. To date, the treatment of patients with ASD remains a complicated problem, for which neuromodulation techniques are a promising solution. This study analyzed the global research situation of neuromodulation techniques in the treatment of ASD from 1992 to 2022, aiming to explore the global research status and frontier trends in this field.

METHODS

The Web of Science (WoS) was searched for literature related to neuromodulation techniques for ASD from 1992 to October 2022. A knowledge atlas to analyze collaboration among countries, institutions, authors, publishing journals, reference co-citation patterns, keyword co-occurrence, keyword clustering, and burst keywords was constructed using Rstudio software, CiteSpace, and VOSviewer.

RESULTS

In total, 392 publications related to the treatment of ASD using neuromodulation techniques were included. Despite some fluctuations, the number of publications in this field has shown a growing trend in recent years. The United States and Deakin University are the leading country and institution in this field, respectively. The greatest contributing authors are Peter G Enticott, Manuel F Casanova, and Paul B Fitzgerald et al. The most prolific and cited journal is Brain Stimulation and the most commonly co-cited journal is The Journal of Autism and Developmental Disorders. The most frequently cited article was that of Simone Rossi (Safety, ethical considerations, and application guidelines for the use of transverse magnetic stimulation in clinical practice and research, 2009). "Obsessive-compulsive disorder," "transcranial direct current stimulation," "working memory," "double blind" and "adolescent" were identified as hotspots and frontier trends of neuromodulation techniques in the treatment of ASD.

CONCLUSION

The application of neuromodulation techniques for ASD has attracted the attention of researchers worldwide. Restoring the social ability and improving the comorbid symptoms in autistic children and adults have always been the focus of research. Neuromodulation techniques have demonstrated significant advantages and effects on these issues. Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are new therapeutic methods introduced in recent years, and are also directions for further exploration.

Knowledge Atlas of the Co-Occurrence of Epilepsy and Autism: A Bibliometric Analysis and Visualization Using VOSviewer and CiteSpace

OBJECTIVE

This study aimed to analyze research on epilepsy in autism and autism in epilepsy using VOSviewer and CiteSpace to identify research hotspots and future directions.

METHODS

We searched the Web of Science Core Collection (WoSCC) for relevant studies about epilepsy in autism and autism in epilepsy published from inception to 31 May 2022. VOSviewer and CiteSpace were used to analyze the authors, institutions, countries, publishing journals, reference co-citation patterns, keyword co-occurrence, keyword clustering, keywords with citation bursts, and other aspects to construct a knowledge atlas.

RESULTS

A total of 473 publications related to epilepsy/autism were retrieved. The number of publications about epilepsy/ASD has generally increased over time, with some fluctuations. The USA (202 papers) and University of California-Los Angeles (15 papers) were the leading country and institution, respectively, in this field. Frye, Richard E. was the most published author (9 papers). Notably, collaboration between institutions, countries, and authors does not appear to be active. Hot topics and research frontiers include intellectual disability and exploring the mechanism of epilepsy/ASD from a genetics perspective.

CONCLUSION

This analysis identified the most influential publications, authors, journals, institutions, and countries in the field of epilepsy/ASD research. Using co-occurrence and evolution analyses, the status of the field was identified and future trends were predicted.

Diagnostic Challenges of High-Functioning Autism Spectrum Disorder in Females

In the last decade, research about distinct female phenotypes in autism spectrum disorders has gained momentum. These patients are often undiagnosed since they do not meet the diagnostic criterion. And since the current standardized instruments are based on the same criterion, these assessments may often lead to false negative results. In clinical settings these patients have a distinct presentation, challenges, and impairments. These findings are useful in understanding, early identification, and effectively treating these individuals. We present a case series to highlight these issues and summarize the recent advances in research.

Transcutaneous Electrical Acupoint Stimulation in Early Life Changes Synaptic Plasticity and Improves Symptoms in a Valproic Acid-Induced Rat Model of Autism

Autism spectrum disorder (ASD) is a developmental disorder characterized by social behavior deficit in childhood without satisfactory medical intervention. Transcutaneous electrical acupoint stimulation (TEAS) is a noninvasive technique derived from acupuncture and has been shown to have similar therapeutic effects in many diseases. Valproic acid- (VPA-) induced ASD is a known model of ASD in rats. The therapeutic efficacy of TEAS was evaluated in the VPA model of ASD in the present study. The offspring of a VPA-treated rat received TEAS in the early life stage followed by a series of examinations conducted in their adolescence. The results show that following TEAS treatment in early life, the social and cognitive ability in adolescence of the offspring of a VPA rat were significantly improved. In addition, the abnormal pain threshold was significantly corrected. Additional studies demonstrated that the dendritic spine density of the primary sensory cortex was decreased with Golgi staining. Results of the transcriptomic study showed that expression of some transcription factors such as the neurotrophic factor were downregulated in the hypothalamus of the VPA model of ASD. The reduced gene expression was reversed following TEAS. These results suggest that TEAS in the early life stage may mitigate disorders of social and recognition ability and normalize the pain threshold of the ASD rat model. The mechanism involved may be related to improvement of synaptic plasticity.

Executive function, motivation, and emotion recognition in high-functioning autism spectrum disorder

BACKGROUND

Several neurocognitive theories have been put forward to explain autism spectrum disorder (ASD). However, the specificity of executive cognitive, motivational (i.e., reward-related), and emotion-recognition impairments in ASD, and the role of early language delay in these impairments remain largely unclear.

AIM

This study aimed to examine executive cognitive, motivational, and emotion-recognition functions while considering the potential effect of language delay in ASD.

METHODS

Twenty-two adolescents with high-functioning ASD (20 males) and 22 typically developing (TD) adolescents (16 males) aged 11-18 years were recruited. Each completed seven computerized tasks measuring executive cognitive (i.e., set-shifting, inhibition, updating, and access/generativity), motivational (i.e., flexible reinforcement learning and affective decision-making), and emotion-recognition functions (i.e., facial emotion recognition).

RESULTS

We found that ASD participants with early language delay (n = 10) had poorer executive cognitive, motivational, and emotion-recognition functioning than TD controls, and had poorer executive cognitive and motivational functioning than ASD participants without language delay (n = 12). ASD participants without language delay only had poorer emotion recognition than TD controls.

CONCLUSION AND IMPLICATIONS

These preliminary findings suggest impairments in executive cognitive and motivational functions as well as emotion recognition in ASD with language delay, and impairment only in emotion recognition in ASD without language delay. They implicate a potential partial distinction in mental abilities between ASD with and without early language delay, highlighting the importance of considering language delay when evaluating executive cognitive and motivational functions in ASD.

"In Medical School, You Get Far More Training on Medical Stuff than Developmental Stuff": Perspectives on ASD from Ontario Physicians

This study investigated the knowledge and perceived competence of Ontario physicians regarding the diagnosis and treatment of ASDs. Previous research demonstrates that many physicians would like more education regarding diagnosis and treatment of autism spectrum disorders (ASDs). Twenty-seven Ontario physicians filled out a questionnaire and participated in a semi-structured interview. Findings revealed that despite participants' high perceived knowledge regarding diagnosis and treatment of ASDs, they feel uncomfortable in providing care for this population. Furthermore, many participants stated diagnosing and treating ASDs is not within their scope of practice. Findings have implications for increasing physicians' knowledge of diagnosis and treatment of ASDs as well as what is required to enhance healthcare for individuals with ASDs and their families.

Subtyping the Autism Spectrum Disorder: Comparison of Children with High Functioning Autism and Asperger Syndrome

Since Hans Asperger's first description (Arch Psych Nervenkrankh 117:76-136, 1944), through Lorna Wing's translation and definition (Psychol Med 11:115-129, 1981), to its introduction in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM, 1994), Asperger Syndrome has always aroused huge interest and debate, until vanishing in the DSM fifth edition (2013). The debate regarded its diagnostic validity and its differentiation from high functioning autism (HFA). The present study aimed to examine whether AS differed from HFA in clinical profiles and to analyze the impact of DSM-5's innovation. Differences in cognitive, language, school functioning and comorbidities, were revealed when 80 AS and 70 HFA patients (3-18 years) were compared. Results suggested that an AS empirical distinction within autism spectrum disorder should be clinically useful.

Cluster analysis of autism spectrum disorder symptomatology: Qualitatively distinct subtypes or quantitative degrees of severity of a single disorder?

The decision to collapse several related disorders into a single diagnosis of Autism Spectrum Disorder (ASD) generated significant controversy and debate. There has been mixed evidence as to whether various ASD subtypes are qualitatively distinct or if they exist on a spectrum of symptom severity. The present study conducted a two-step cluster analysis of major ASD symptoms in a sample of 147 young males with ASD aged between 6yr and 18yr with IQ > 70. Results indicated that a two-cluster solution (high and low severity of ASD symptomatology) was reliable and valid. Further, the construct of challenging behaviour was not a necessary component of the two-cluster solution, verifying the new conceptualisation of ASD. Further replication of these findings with other subsets of individuals with ASD is needed.

Social communication disorder: a narrative review on current insights

Social communication disorder (SCD) is a novel diagnosis listed under the rubric of communication disorders within the Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) and it is reported to be characterized by impairment in use of verbal and nonverbal communication for social aims. This review attempts to summarize the current understanding of the SCD concept along with its evolution and presents data from previous studies conducted. Suggestions for further research are also delineated. As listed in DSM-5, the criteria for this novel diagnosis are vague, display elevated comorbidity with other neurodevelopmental disorders and other childhood psychopathologies, and show partial overlap with autistic spectrum disorders both in terms of genetics and family histories. Data on cross-cultural presentations and temporal stability are also limited. The social communication model proposed by Catani and Bambini may help integrate the neurobiological findings pertaining to SCD. Valid and reliable assessment methods need to be developed for SCD. This may involve either development of novel instruments capturing the DSM-5 criteria or application of statistical methods such as item response theory to existing instruments. The relationships between broad autism phenotype, pragmatic language impairment, nonverbal learning disorder, learning disorders, autistic spectrum disorders, and SCD should be evaluated with further studies.

Asperger Syndrome and Schizophrenia: A Comparative Neuropsychological Study

There has been an increasing interest in possible connections between autism spectrum disorder (ASD) and schizophrenia in the last decade. Neuropsychological comparison studies have, however, been few. The present study examined similarities and differences in intellectual and executive functioning between adults with Asperger syndrome (AS) and adults with schizophrenic psychosis (SP). A group with AS and a group with SP were assessed neuropsychologically with WAIS-III and D-KEFS. Similarities were found between groups, as displayed by an uneven cognitive profile, limitations in working memory, processing speed and some aspects of executive functioning. Full Scale IQ was higher in the AS group. These results add to the current research illuminating similarities and differences between ASD and schizophrenia on a cognitive level.

ADHD-related symptoms and attention profiles in the unaffected siblings of probands with autism spectrum disorder: focus on the subtypes of autism and Asperger's disorder

BACKGROUND

The presence of attention-deficit/hyperactive disorder (ADHD) symptoms and impaired attention performance are commonly noted in individuals with autism spectrum disorder (ASD). However, little is known about attention performance in their unaffected siblings. This study aimed to investigate the ADHD-related traits and attention performance in unaffected siblings of probands with autism and Asperger syndrome (AS), as well as the clinical correlates of ADHD-related traits.

METHODS

We assessed the intention, hyperactivity-impulsivity, and oppositional symptoms, and attention profiles of 199 probands with a diagnosis of ASD (122 autism, 77 AS), their unaffected siblings, and 196 typically developing controls (TD) by their parents' reports on the ADHD-related symptoms and the Connors' Continuous Performance Test (CCPT), respectively.

RESULTS

Compared to TD, unaffected siblings of ASD probands were more hyperactive/impulsive and oppositional, particularly unaffected siblings of AS probands. In CCPT, unaffected siblings of AS have intermediate levels of performance between probands with AS and TD on focused attention and sustained attention but were not statistically different from AS probands or TD in these attention profiles. In contrast, unaffected siblings of autism probands have significantly better CCPT performance when compared to autism probands but not to TD. In addition, stereotyped behaviors predicted ADHD-related traits in both sibling groups, but distinctive patterns of other correlates for ADHD-related traits were found between the two sibling groups.

CONCLUSIONS

This work suggested that unaffected siblings of AS, but not autism, have more hyperactive/impulsive traits and a trend of pervasive attention deficits assessed by CCPT which might serve as potential endophenotypes for genetic studies in AS.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01582256.

Color Vision Losses in Autism Spectrum Disorders

Autism spectrum disorders (ASDs) are neurodevelopmental conditions characterized by impairments in social/communication abilities and restricted behaviors. The present study aims to examine color vision discrimination in ASD children and adolescents without intellectual disability. The participants were also subdivided in order to compare color vision thresholds of autistic participants and those who achieved diagnostic criteria for Asperger Syndrome (AS). Nine subjects with autism, 11 participants with AS and 36 typically developing children and adolescents participated in the study. Color vision was assessed by the Cambridge Color Test (CCT). The Trivector protocol was administered to determine color discrimination thresholds along the protan, deutan, and tritan color confusion lines. Data from ASD participants were compared to tolerance limits for 90% of the population with 90% probability obtained from controls thresholds. Of the 20 ASD individuals examined, 6 (30%) showed color vision losses. Elevated color discrimination thresholds were found in 3/9 participants with autism and in 3/11 AS participants. Diffuse and tritan deficits were found. Mechanisms for chromatic losses may be either at the retinal level and/or reflect reduced cortical integration.

Altered GABAergic Signaling in Brain Disease at Various Stages of Life

In the healthy brain, gamma-aminobutyric acid (GABA) is regulated by neurons and glia. This begs the question: what happens in the malfunctioning brain? There are many reasons why diseases occur, including genetic mutations, systemic problems, and environmental influences. There are also many ways in which GABA can become dysregulated, such as through alterations in its synthesis or release, and changes in systems that respond to it. Notably, dysregulation of GABA can have a large impact on the brain. To date, few reviews have examined brain diseases in which dysregulation of GABA is implicated as an underlying factor. Accordingly, the time is ripe for investigating alterations in GABAergic signaling that may play a role in changes in neuronal activity observed in the major brain disorders that occur during various stages of life. This review is meant to provide a better understanding of the role of GABA in brain health and contributor to social problems from a scientific perspective.

Do Adults with High Functioning Autism or Asperger Syndrome Differ in Empathy and Emotion Recognition?

The present study examined whether adults with high functioning autism (HFA) showed greater difficulties in (1) their self-reported ability to empathise with others and/or (2) their ability to read mental states in others’ eyes than adults with Asperger syndrome (AS). The Empathy Quotient (EQ) and ‘Reading the Mind in the Eyes’ Test (Eyes Test) were compared in 43 adults with AS and 43 adults with HFA. No significant difference was observed on EQ score between groups, while adults with AS performed significantly better on the Eyes Test than those with HFA. This suggests that adults with HFA may need more support, particularly in mentalizing and complex emotion recognition, and raises questions about the existence of subgroups within autism spectrum conditions.

Aripiprazole for the treatment of irritability and aggression in children and adolescents affected by autism spectrum disorders

INTRODUCTION

Aripiprazole is an atypical antipsychotic approved for the treatment of irritability and aggression in children and adolescents aged 6-17 years with autism spectrum disorder.

AREAS COVERED

This review will discuss the drug profile as well as available studies of aripiprazole in individuals with autism spectrum disorder as documented in prospective randomized controlled trials. Expert commentary: The heterogeneity of autism spectrum disorder has implications for assessing the effectiveness and safety of aripiprazole as it may not produce the same results in two individuals with the same diagnosis but different etiologies. Subgrouping of patients according to their overall presentation of symptoms may therefore be warranted. In addition, consideration should be given to the potential causes of irritability and aggression, such as coexisting medical conditions and environmental factors including inappropriate intervention of parents and teachers. In these cases, the identification of the underlying cause is important because the appropriate management.

Neuroanatomy of Individual Differences in Language in Adult Males with Autism

One potential source of heterogeneity within autism spectrum conditions (ASC) is language development and ability. In 80 high-functioning male adults with ASC, we tested if variations in developmental and current structural language are associated with current neuroanatomy. Groups with and without language delay differed behaviorally in early social reciprocity, current language, but not current autistic features. Language delay was associated with larger total gray matter (GM) volume, smaller relative volume at bilateral insula, ventral basal ganglia, and right superior, middle, and polar temporal structures, and larger relative volume at pons and medulla oblongata in adulthood. Despite this heterogeneity, those with and without language delay showed significant commonality in morphometric features when contrasted with matched neurotypical individuals (n = 57). In ASC, better current language was associated with increased GM volume in bilateral temporal pole, superior temporal regions, dorsolateral fronto-parietal and cerebellar structures, and increased white matter volume in distributed frontal and insular regions. Furthermore, current language-neuroanatomy correlation patterns were similar across subgroups with or without language delay. High-functioning adult males with ASC show neuroanatomical variations associated with both developmental and current language characteristics. This underscores the importance of including both developmental and current language as specifiers for ASC, to help clarify heterogeneity.

Update on diagnostic classification in autism

PURPOSE OF REVIEW

In the lead up to and following the recent publication of the DSM-5, the diagnostic construct of autism has received intense scrutiny.

RECENT FINDINGS

This article briefly reviews the history of the diagnosis of autism, the changes that have occurred in the diagnosis over time, and the rationale for change. The most significant changes being introduced with the DSM-5 are highlighted, as well as some of the concerns that will be a focus of attention with respect to the potential impacts going forward.

SUMMARY

The categorical divisions that characterized the pervasive developmental disorders are now collapsed into a single entity, autism spectrum disorder. The final DSM-5 criteria have yet to be formally compared prospectively against prior criteria, but early indications suggest that the boundaries around the pervasive developmental disorders have not been substantially altered.