Marc J. Tassé

• PhD
• Professor (Full) at The Ohio State University

This study explores social outcomes for adults with autism spectrum disorder (ASD) in comparison to adults with developmental disabilities other than ASD by investigating the relationships between the constructs Social Participation and Relationships, Social Determination, and Personal Control. Structural equation modeling (SEM) was used to test a...

Abstract This study used data from the National Core Indicators (NCI) Survey to derive an empirically validated measurement model for social outcomes and associated constructs for both individuals with Autism Spectrum Disorder (ASD) and individuals with other disabilities. Items consistent with the survey structure of the NCI were selected as initi...

Abstract The World Health Organization (WHO) is in the process of seeking input from professional stakeholder groups and consumers regarding the draft proposals of the 11th edition of the International Classification of Diseases (ICD-11). The American Association on Intellectual and Developmental Disabilities (AAIDD) convened a small group of disti...

This article updates the current conceptualization, measurement, and use of the adaptive behavior construct. Major sections of the article address an understanding of the construct, the current approaches to its measurement, four assessment issues and challenges related to the use of adaptive behavior information for the diagnosis of intellectual d...

The term “diagnostic overshadowing” was coined in 1982 (Reiss et al., 1982) to refer to a phenomenon in which a diagnosis of intellectual disability (ID) is so salient that it “overshadows” the presence of other mental health conditions, whose symptoms are falsely attributed to the ID. Much of the research on this topic was conducted more than 20 y...

Importance Communicating clearly about who is included in a population group is a critical element to effective dissemination and knowledge transfer. This narrative review highlights the inconsistency as it relates to communicating about individuals with intellectual disability (ID) and developmental disability (DD). Observations There is enormous...

Diagnostic overshadowing is a bias in which symptoms of a psychological disorder are falsely attributed to a known diagnosis of intellectual disability. This systematic review evaluated all research on diagnostic overshadowing conducted to date, including dissertations and peer-reviewed journal articles. In total, 25 studies were included in this r...

Background: The presence during the developmental period of significant limitations in adaptive behavior is an essential component along with deficits in intellectual functioning for diagnosing intellectual disability. Only the Diagnostic Adaptive Behavior Scale (DABS) specifically assesses the required significant limitations in adaptive behavior...

Supporting individuals with intellectual disability or related neurodevelopmental disabilities should access all available and types of supports that can enhance their personal independence, autonomy, health, safety, and overall quality of life. Herein we discuss the value of exploring the use of technology solutions as a under-utilized type of sup...

People with intellectual disability or related neurodevelopmental disorders may present the full range of psychiatric and behavioral disorders seen in the general population. In fact, research has shown that they are more susceptible to presenting psychiatric disorders and/or challenging behaviors. When a person with intellectual disability or a re...

The construct of belonging has been studied in many marginalised student groups yet has been understudied among students with intellectual disability. The present study used a large dataset from the United States to quantitatively investigate the construct of belonging among 7th to 12th grade students with the educational classification of "intelle...

Adaptive behavior and intelligence are both essential components of defining and diagnosing intellectual disability. The exact relationship between these two constructs still warrants some clarification. Previous studies have examined the correlation between adaptive behavior and intelligence and have reported differing results. Overall, there seem...

The aim of this study was to develop a transcultural adaptation of the Diagnostic Adaptive Behavior Scale (DABS) in French and to perform a field evaluation of the adapted version of the tool (DABS-F). Eight experts in intellectual and developmental disabilities (IDD) and two professional translators formed two committees to translate the instrumen...

Background: Dramatic changes in societal approaches to people with intellectual and developmental disabilities (IDD), and the services and supports they receive are reflected in a new paradigm that we name the shared citizenship paradigm. The shared citizenship paradigm (1) incorporates an updated and contemporary set of values and beliefs about p...

The Nisonger Child Behavior Rating Form (NCBRF) was developed to specifically screen psychopathology and problem behavior in children and adolescents with IDD. This study aimed to update the NCBRF to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) and screen for the most prevalent psychopathologies that affect childre...

Changes in the field of intellectual and developmental disabilities (IDD) over the last 5 decades has resulted in the emergence of the shared citizenship paradigm. This paradigm is currently guiding the development of IDD-related policies and practices, and providing a framework for application, research-based inquiry, and evaluation. A shared citi...

The aim of this study was to develop a transcultural adaptation of the Diagnostic Adaptive Behavior Scale (DABS) in French and to perform a field evaluation of the adapted version of the tool (DABS-F). Eight experts in intellectual and developmental disabilities (IDD) and two professional translators formed two committees to translate the instrumen...

This article addresses the need to clearly understand professional responsibility and the critical role it plays in the lives of individuals with intellectual and developmental disabilities (IDD), in shaping professions for the better, and in enhancing the functioning of society for the benefit of all. Understanding professional responsibility is e...

People with disorders of intellectual development (PWDID) are more vulnerable to anxiety and stress-related disorders and frequently misdiagnosed especially in those with more severe disability. Accurate diagnosis culminating in a successful outcome may involve placing particular emphasis on obtaining a collateral history from significant caregiver...

At one time, clinicians assumed that people with intellectual disability lacked the cognitive capacity to develop mental illness. We now know that intellectual disability (ID) does not offer any protection against experiencing the full range of psychiatric disorders (Fletcher et al., 2016). In fact, people with ID may be more susceptible than peopl...

Intelligence and intellectual disability (ID) or intellectual developmental disorder (IDD), according to the most recent terminology, might not be natural kinds but the result of a historically contingent human attempt of self-definition and self-characterization. The seeds of intelligence as a measure for classifying humans were sown at the end of...

Background: The Diagnostic Adaptive Behavior Scale (DABS) is a short scale with excellent properties to assess the conceptual, social, and practical adaptive behavior domains for the diagnosis of intellectual disability (ID) in individuals aged 4–21 years. Aims: Investigate the test-retest and inter-respondent reliability of the Italian adaptation...

In this national survey of departments of developmental disabilities services across the United States, we attempted to establish the number of the states that made remote support services available as an authorized service in some state Medicaid funded developmental disabilities waiver programs. Remote support services were defined as a service th...

It is estimated that approximately 41% of adults with intellectual and developmental disability (IDD) are served through the developmental disabilities (DD) system in the US. The remaining 59% include individuals who meet diagnostic criteria but are not actively receiving paid services or may not be known to the DD system. Scholars have referred to...

This paper reviews the current state of knowledge on psychological interventions with empirical evidence of efficacy in treating common psychiatric and behavioral disorders in people with intellectual disability (ID) at all stages of their life. We begin with a brief presentation of what is meant by psychiatric and behavioral disorders in this popu...

Background Mental health conditions are common among individuals with intellectual disability. Under recognition of mental health disorders leading to unmet treatment needs is common in this population. This article addresses one major contributing factor, the lack of cognitively accessible self-report measures for individuals with intellectual dis...

Definition of Intellectual Disability and Assumptions Regarding Its Application (Schalock, Luckasson, & Tassé, 2021) Intellectual disability (ID) is characterized by significant limitations both in intellectual functioning and in adaptive behavior as expressed in conceptual, social, and practical adaptive skills. This disability originates durin...

Previous research suggests that residence in non-metropolitan areas is associated with lower access to preventive care and poorer health. However, this research has been largely restricted to the general population, despite data demonstrating disparities in health status and access to healthcare services for people with intellectual and development...

There has been a significant transformation in the field of intellectual and developmental disabilities (IDD) over the last 5 decades. Although this transformation has profoundly influenced multiple stakeholders, the field is currently at a critical juncture and facing a number of social and political challenges. Given the relevance of the question...

Significant international work in the field of intellectual disability (ID) over the last decade has resulted in an emerging consensus regarding the definition of ID, the criteria used to diagnose a person with ID, the classification of individuals who have been diagnosed with ID, and the planning of individualized supports for people with ID. This...

Background: Given the importance of adaptive behaviour (AB) for the identification of intellectual disability and the design of intervention plans for people with Down syndrome (DS), this cross- sectional study explored AB in infants with DS, compared to infants with typical development (TD). Method: we evaluated 60 infants (10–36 months) with ABAS...

Objective To identify and summarize clinical practice guidelines for Autism Spectrum Disorder (ASD) and Intellectual Disability (ID) for the Package of Interventions for Rehabilitation for the World Health Organization (WHO). Data Sources Academic databases, Google Scholar, guideline databases, and professional society websites were searched using...

The aim of this study was to do a French adaptation of the Diagnostic Adaptive Behaviour Scale (DABS). This is the first assessment instrument specifically developed to be reliable at the cut-off point that established significant limitations in adaptive behaviour and assist clinicians in the determination of intellectual disability. The DABS was a...

Our understanding of health has changed substantially since the World Health Organization initially defined health in 1948 as “a state of complete physical, mental and social and well-being and not merely the absence of disease or infirmity”. These changes include reconceptualizing health on a continuum rather than as a static state, and adding exi...

Adaptive behavior is an important construct that is involved in the diagnosis and determination of the severity of a number of neurodevelopmental disorders. Adaptive behavior is also associated with greater independence and overall quality of life. Adaptive behavior is defined as the skills that are learned and performed to meet the everyday demand...

Objective: Autism spectrum disorder (ASD) and intellectual disability (ID) were selected for inclusion in the development of a Package of Interventions for Rehabilitation for the World Health Organization (WHO). Here, we describe results of a search of guidelines for these conditions. Methods: A literature search for clinical practice guidelines wa...

The AAIDD definition manual leads the field in understanding, diagnosing, and classifying the construct of intellectual disability (ID). The 12th edition integrates the findings and developments of the last 10 years and presents the operational definition in a systematic approach to diagnosis, optional subgroup classification, and planning of syste...

Previous studies have reported an inverse relationship between adaptive behavior and challenging behaviors in individuals with ID. However, it is unclear which characteristics might influence this relationship in individuals with ID and co-occurring conditions. We found a positive correlation between adaptive behavior (Vineland-II) and challenging...

Background: The Nisonger Child Behavior Rating Form (NCBRF) allows for the assessment of frequency and severity of challenging behaviours of individuals with ID with one combined rating. However, frequency and severity rating of challenging behaviours may be in disagreement. Therefore, the efficacy of frequency and severity independent ratings for...

Background: Studies have reported unmet health needs in individuals with intellectual disability (ID). This study illustrated and analysed patterns of healthcare services utilization among people with intellectual disability and compared their use to that of the general population. Method: Participants (N = 791, aged 15-82) were mainly recruited...

Studies have shown that executive function abilities are related and have predictive power over adaptive behaviour in both typical and atypical populations. This study examined the relationship between executive functioning and adaptive behaviour in adolescents with Down syndrome, as it has not been studied before in this population. We propose and...

Background: The use of remote support technologies is a newer form of service that can contribute to increased independence while giving adults with intellectual and developmental disabilities a sense of home safety. This research reviewed the use of remote support services, which is a waiver service that includes smart home technologies and remot...

This chapter provides an overview of individuals with intellectual and developmental disabilities (IDD), focusing on the importance of behavioral health professionals to be prepared to competently provide treatment to individuals with disabilities and to recognize individuals with IDD as a unique culture rather than a population that should be path...

Challenges in collecting comprehensive health surveillance data on people with intellectual and developmental disabilities (IDD) are numerous. A number of important issues and strategies are discussed in the articles contained in this special issue of Intellectual and Developmental Disabilities. In this article, we focus on the advances and tools a...

Background: The field of intellectual and developmental disabilities (IDD) is currently experiencing a significant transformation that encompasses an integrated approach, especially regarding shared aspects such as a focus on the human and legal rights, the eligibility for services and supports, and an emphasis on individualized supports provided...

The aim of this study is to determine validity and reliability studies of the Support Intensity Scale for Adults. For this purpose, the Turkish validity and reliability of the scale has been tested in a large sample.

This qualitative study was carried out in Spain with the aim of identifying the changes that the health system should make to improve healthcare access for older adults with intellectual disability. Three hundred and sixty‐nine family members and professionals expressed their opinion on how healthcare access could be improved. Participants responde...

This study examined the role of parent expectations and adaptive behavior in predicting outcomes for youth with intellectual disability. A sample of students with intellectual disability were drawn from the National Longitudinal Transition Study-2 for inclusion in this study. Four latent variables were created: demographic factors, adaptive behavio...

Down syndrome (DS) is characterized by difficulties in both intellectual functioning and adaptive behavior. These sets of abilities are considered as separate but related domains with small to moderate correlations. The main objective of this study was to explore the relationship of intellectual functioning and adaptive behavior in adolescents with...

Background We present the work conducted to arrive at deriving behavioural indicators that could be used to guide clinical judgement in determining the presence and severity of deficits in intellectual functioning and adaptive behaviour for the purpose of making a diagnosis of disorders of intellectual development. Methods An interdisciplinary exp...

This article describes a holistic theoretical framework that can be used to explain intellectual disability (ID) and organize relevant information into a usable roadmap to guide understanding and application. Developing the framework involved analyzing the four current perspectives on ID and synthesizing this information into a holistic theoretical...

This book presents clinical and legal information on the issues related to the death penalty involving people with intellectual disability. The book presents clinical information on the determination of intellectual disability along with best practices in making a clinical diagnosis. The book also discusses the US Supreme Court decisions relevant t...

Background: People with developmental disabilities experience worse health than typically developing peers. This health differential is often described in terms of health disparities, which refers to differences caused or exacerbated by social or access issues. Objective: the goal of this study was to compare the weight status and health conditions...

Background: Adults with disabilities are employed at a significantly lower rate than adults without disabilities. Of adults with disabilities in the workforce, more individuals work in a facility setting rather than a community setting, despite efforts to improve community inclusion. Choice-making has been proposed as a predictive factor for emplo...

The Supports Intensity Scale-Children's version (SIS-C) was developed to provide a standardized measure of support needs of children with intellectual disability. Over half of the norming sample had a secondary diagnosis of autism. Using this subset of the sample, we engaged in exploratory analysis to examine the degree to which latent clusters wer...

This pilot study was designed to explore the potential impact of participation in the Hunter Heartbeat Method, a drama-based social skills intervention, on the core symptoms of autism spectrum disorder (ASD). A sample of 10 children with ASD participated in this study. Children were assessed at three time-points: before the start of the interventio...

Providing key information for students or professionals in the fields of criminology, education, psychology, law, and law enforcement, this book documents the legal and clinical aspects of the issues related to intellectual disability and the death penalty. Written by two nationally recognized experts, this book provides a comprehensive review of t...

Intellectual disability originates during the developmental period and is characterized by significant limitations both in intellectual functioning and in adaptive behavior as expressed in conceptual, social, and practical adaptive skills. In this article, we present a brief history of the diagnostic criteria of intellectual disability for both the...

This preliminary report describes the Hunter Heartbeat Method, a drama-based social skills intervention designed to improve the social interaction, pragmatic language, and facial-emotion recognition skills of individuals with autism spectrum disorder. Fourteen children with autism spectrum disorder were recruited for the first-ever systematic imple...

Mirroring the evolution of the conceptualization of autism has been changes in the diagnostic process, including the most recent revisions to the DSM-5 and the addition of severity-based diagnostic modifiers assigned on the basis of intensity of needed supports. A review of recent literature indicates that in research stratifying individuals on the...

The authors assessed available prevalence information regarding neuropsychiatric conditions among adults with Down syndrome (DS) and compared these findings among adults with other intellectual disability (non-DS). The study entailed a survey of 291 adults with DS living in Ohio (USA). Twenty-three percent of adults with DS reported having a co-occ...

The Diagnostic Adaptive Behavior Scale (DABS) was developed using item response theory (IRT) methods and was constructed to provide the most precise and valid adaptive behavior information at or near the cutoff point of making a decision regarding a diagnosis of intellectual disability. The DABS initial item pool consisted of 260 items. Using IRT m...

Background: The Diagnostic Adaptive Behaviour Scale (DABS) is a new standardised adaptive behaviour measure that provides information for evaluating limitations in adaptive behaviour for the purpose of determining a diagnosis of intellectual disability. This article presents validity evidence and reliability data for the DABS. Method: Validity e...

Background The operationalisation of quality of life for people with more severe disabilities has been acknowledged in the published research for more than two decades. This study aims to contribute to our knowledge and understanding of the quality of life of adults with severe disabilities by developing a set of quality of life indicators appropri...

Contexte. Les parents d’enfants ayant une DI ou un TSA rapportent généralement un stress plus élevé que les parents d’enfants à développement typique, ce qu’on a peu étudié au Québec. Méthode. Quatre groupes de 144 parents (ayant un enfant sans DI ni TSA; avec DI; avec TSA; avec DI et TSA) ont complété des mesures de stress parental, de soutien soc...

The Diagnostic Adaptive Behavior Scale (DABS) was constructed with items across three domains — Conceptual, Social, and Practical adaptive skills — and normed on a representative sample of American individuals from 4 to 21 years of age. The DABS was developed to focus its assessment around the decision point for determining the presence or absence...

Three separate studies were undertaken to examine the reliability and validity of the Supplemental Protection and Advocacy Scale (P&A Scale) of the Supports Intensity Scale (SIS). In Study 1, the interrater reliability of the P&A Scale was investigated when interviewers were trained in SIS administration and scoring. Pearson's product moment coeffi...

The main aims of the present study were to examine the factor structure and the internal consistency of the factors in the French version of the Reiss Screen of Maladaptive Behavior in a French-speaking European sample. The prevalence of psychopathology and the influence of associated factors were also examined. The Reiss Screen was administered to...

Abstract The World Health Organization (WHO) is in the process of developing the 11th edition of the International Classification of Diseases (ICD-11). Part of this process includes replacing mental retardation with a more acceptable term to identify the condition. The current international consensus appears to be replacing mental retardation with...

Abstract Some studies have reported the presence of health disparities in people with intellectual disability. This study compared the prevalence of chronic health conditions between people with and without intellectual disability (ID). Health-related data for 791 people with ID were collected through a province-wide mail survey in Quebec, Canada....

People with and without disabilities universally value the goals of greater control and self-determination, inclusion and participation in their school or community, and enhanced social inclusion. Technology is an important support in achieving these goals. In this manuscript we examine the intensity of support needs, as measured by the Supports In...

There is a growing body of research on the construct of support needs in individuals with intellectual disability (ID). An increasing emphasis is being placed on measuring and understanding the needs for supports and the factors that drive the intensity of these support needs. Prior research has firmly established that individuals with ID are more...

The progressive obsolescence of IQ test norms and associated score inflation (i.e., the Flynn effect) may have literal life and death significance in capital mental retardation determinations (i.e., Atkins hearings). Hagan, Drogin, and Guilmette (2008) asserted that IQ score corrections for the Flynn effect were inconsistent with a “standard of pra...