DM-ID Clinical Guide

Chapter 1

Introduction

Robert Fletcher, D.S.W, ACSW.
Earl Loschen, M.D.
Chrissoula Stavrakaki, M.D., Ph.D.
Michael First, M.D.

 “We as a Nation have long neglected the mentally ill and the mentally retarded. This neglect must end, if our Nation is to live up to its own standards of compassion and dignity and achieve the maximum use of its manpower.”
John F. Kennedy, address to Congress on February 5, 1963

The DM-ID

Diagnostic Manual – Intellectual Disability (DM-ID): A Clinical Guide for Diagnosis of Mental Disorders in Persons with Intellectual Disability focuses on issues related to diagnosis in people with Intellectual Disability (ID), the limitations in applying DSM-IV-TR criteria to people with ID, and adaptation of the diagnostic criteria.

It has been abridged for clinical usefulness from The Diagnostic Manual – Intellectual Disability (DM-ID): A Textbook of Diagnosis of Mental Disorders in Persons with Intellectual Disability which was developed by the National Association for the Dually Diagnosed (NADD), in association with the American Psychiatric Association (APA), and is a diagnostic manual designed to be an adaptation of the DSM-IV-TR. Grounded in evidence-based methods and supported by the expert-consensus model, the DM-ID(Textbook) offers a broad examination of the topic, including a description of each disorder, a summary of the DSM-IV-TR diagnostic criteria, a review of the research and an evaluation of the strength of evidence supporting the literature conclusions, a discussion of the etiology and pathogenesis of the disorders, and adaptations of the diagnostic criteria for persons with Intellectual Disability (ID).

The goal of both volumes is to facilitate a more accurate psychiatric diagnosis of people with ID. Chapters in the DM-ID cover special issues (i.e., assessment and diagnostic procedures and presentations of behavioral phenotypes of genetic disorders) as well as the individual DSM-IV-TR categories. For each disorder, descriptive text and details of how to apply diagnostic criteria, as well as tables of adapted diagnostic criteria, are included.

In addition to adapting the DSM-IV-TR diagnostic criteria where appropriate, the DM-ID provides advice about and considerations for assessing and diagnosing individuals with ID and coexisting mental health needs. In some cases, it is not so much that the criteria need to be adapted, as that a different method of eliciting the necessary information must be used. Information is provided in recognizing common behaviors of individuals with intellectual disabilities and in how to differentiate these behaviors from psychiatric disorders.

The Problem

Although psychiatric disorders in persons with ID are common, they are often not appropriately identified. The provision of adequate mental health treatment for people with ID continues to be lacking, in part, because reliable psychiatric diagnosis remains a clinical challenge. Determining an accurate psychiatric diagnosis becomes especially difficult as the level of intellectual functioning declines.

Children and adults who have ID coexistent with psychiatric disorders may be one of the most underserved populations in the United States. These individuals may fall through the cracks in service delivery systems when neither the local mental health service system nor the developmental disability service system is willing or able to assume responsibility for their treatment, services, and support. Individuals with ID have been estimated to be 2 to 4 times more likely than those in the general population to experience psychiatric disorders. Researchers have found that as many as one third or more of all people with ID have significant behavioral, mental, or personality disorders requiring mental health services. Often people with ID who exhibit psychiatric problems are denied services or receive inappropriate treatment and services.

During the past few decades, there have been important developments in the field of mental health care for people with ID. The National Association for the Dually Diagnosed (NADD) has been instrumental in marshaling national and international attention, providing education and training, and disseminating relevant clinical and policy issues. In spite of these encouraging developments, however, there remain significant obstacles hindering appropriate care and treatment for this underserved population. One key problem is the absence of a diagnostic system appropriate for clinical use with the diverse population of people with ID. As a result, individuals may receive no psychiatric diagnosis even when a mental disorder exists, or they may receive an inaccurate or inappropriate diagnosis. Because treatments, services, and supports are tied directly to the accurate evaluation and diagnosis of people who have ID coexistent with mental disorders, the absence of psychiatric diagnoses is a central issue.

Clinicians need a system whereby they can recognize the presence of DSM-IV-TR-documented mental disorders in persons who have limited expressive and receptive language skills. A major potential advantage of the DM-ID is that it may enhance the reliability of psychiatric diagnoses in persons with ID which could ultimately improve treatment outcomes.

There are a number of factors associated with the difficulty of making an accurate diagnosis in people with ID. The applicability of existing standardized classification systems (such as the DSM-IV-TR) for persons with ID has been critically debated in professional literature. To determine whether a person within the general population has been experiencing psychiatric symptoms, a clinician typically relies on the person’s description of his or her experiences and feelings. Individuals with cognitive impairments experience difficulties in receptive and expressive language to varying degrees. Mild limitations in cognitive and verbal skills make it difficult, and severe limitations may make it impossible, for people with ID to articulate such abstract or global concepts as depressed mood or to communicate subtle differences among emotional or motivational states.

Other factors that increase the difficulty in making psychiatric diagnoses include the tendency for some people with ID to attempt to hide their disabilities (to adopt a “cloak of competence”), the tendency not to be forthcoming with respect to self-descriptions, and the tendency for some to try to please the evaluator by answering falsely or in a manner that is inaccurate (“acquiescence bias”). Additionally, the symptoms of diverse psychiatric disorders are often expressed differently in people with ID. Four processes that are common in persons with ID that can influence the diagnostic decision-making process are baseline exaggeration, intellectual distortion, psychosocial masking, and cognitive disintegration.

Another diagnostic challenge is diagnostic overshadowing. Having a diagnosis of ID can overshadow coexisting mental disorders and may predispose practitioners to overlook the presence of psychopathology, because unusual or anomalous behavior is attributed by the clinician to being artifacts of developmental or social delay. For example, a person with Profound ID who is very withdrawn and asocial might be less likely to be labeled as depressed than would a person with average intelligence.

Accurate diagnosis is important because it provides a sound basis for effective treatment. For many patients and their families diagnostic understanding will reduce confusion and uncertainty. Positive treatment outcome is based on an accurate diagnosis. Just as this is true concerning physical health, it is equally true in psychiatric health.

Severe behavioral disturbance in the form of verbal or physical aggression toward others, self-injury (aggression toward self), and property destruction frequently motivates referrals for diagnosis and treatment prescription. Such severe disturbance occurs at a clinically significant rate among people with ID, often threatens the stability of family living or the continuation of community living in a relatively nonrestrictive setting, and can precipitate admission to a public mental health or ID facility. Severe behavioral disturbance of various types occurs among people with Mild to Profound ID. However, it is important to understand that severe behavioral disturbances are not part and parcel of a diagnosis of ID. The presence of clinically significant behavioral disturbances mandates a thorough clinical diagnostic evaluation to determine the presence of comorbid mental disorders that may be responsible for the behavioral disturbance. The extent to which behavioral disturbances represent symptom equivalents for symptoms such as depression and anxiety, especially in individuals with severe and profound ID, has been the subject of considerable debate, which remains to be elucidated by further research.

Classification and Diagnosis of Mental Illness

The clinician is faced with certain challenges when an individual with ID presents with disturbed or disturbing behavior. There has been controversy found in the literature concerning the issue of reliability in making specific DSM-IV-TR diagnosis in persons with ID, especially those with more severe impairment and intellectual function. Some researchers assert that as intelligence decreases the validity of psychiatric diagnosis for individuals with ID tends to decrease. They explain this as the result of both an increase in nonspecific organic factors and the relative inaccessibility of the individual’s inner life as productive speech decreases with the increased severity of impairment. Despite a general consensus that mental disorders can be diagnosed using standard diagnostic criteria for people with mild ID and reasonably good communicative skills, clinicians generally acknowledge the increased difficulty for individuals with more severe ID and poor verbal skills.

In fact, the DSM-IV-TR itself recognizes that some diagnostic criteria need to be modified when they are applied to children, both because the symptom profile of some disorders differs in children (for example, the substitution of “irritable mood” for “depressed mood” in the diagnostic criteria for Major Depressive Episode and Dysthymic Disorder in children) and because some diagnostic criteria do not apply to children (for example, there is no requirement in specific phobia descriptions that children recognize that their fears are excessive or unreasonable). Although criteria set modifications have been proposed for different cultural groups—for the medically ill and for geriatric patients among others, as well as those for children—no other modifications are included in the DSM-IV-TR.

Preparation of the DM-ID

In 1998, Robert Fletcher, D.S.W., A.C.S.W., founder and CEO of NADD, submitted a proposal to the NADD Board of Directors with the concept of developing a companion to the DSM-IV to be used to facilitate a more accurate DSM-IV diagnosis for people with ID. He was subsequently appointed Chief Editor to develop, coordinate, and edit this manual, and he appointed Earl Loschen , M.D., Chrissoula Stavrakaki, M.D., Ph.D., and Michael First, M.D. as co-editors.

All major diagnostic categories of mental disorders as defined in the DSM-IV-TR are covered in the DM-ID. For each of these diagnostic categories, a lead person functioned as a chapter coordinator. Each of these chapter coordinators is an expert in the specific diagnostic category under study, and each has made significant contributions to the field. Each chapter coordinator selected a working committee, generally consisting of three to five experts in the field of dual diagnosis, to write a chapter on a specific diagnostic category.

A major thought in writing the DM-ID was the assumption that there was a need to develop adapted criteria of DSM-IV-TR. The editors envisioned that there would be a need to develop two adapted criteria (one for Mild/Moderate ID and other for Severe/Profound ID), each correlated with the DSM-IV-TR criteria. However, as the process has moved forward in the development of this Manual, the editors came to realize that in many diagnostic categories, there is no need to have separate columns for mild/moderate and severe/profound. In fact, the editors identified that in many diagnostic categories, there is no need for a modified criteria.

Obsessive-Compulsive Disorder and Post-Traumatic Stress Disorder

This book diverges from the arrangement of mental disorders in the DSM-IV-TR for Obsessive-Compulsive Disorder and Post-Traumatic Stress Disorder. In the DSM-IV-TR these disorders appear in the chapter on Anxiety Disorders. Here, though, both because of their importance in the ID population and because they are frequently underdiagnosed, Obsessive-Compulsive Disorder and Post-Traumatic Stress Disorder are each assigned their own chapter.

Expert Consensus

There is a general dearth of research in the area of co-occurring ID and mental illness. Expert consensus helps bridge the gap between clinical research and clinical practice. In the absence of research, the collective opinion of experts is considered a useful and appropriate guide. For this reason, the authors of the DM-ID relied upon an expert consensus model in their work.

Grounded in the expert consensus model, each chapter grew out of a critical review of the literature. All authors on a team reviewed and commented upon each other’s written contributions, resulting in changes and improvements. The entire manuscript was submitted to seven experts for peer review (see list of External Peer Reviewers at front of book). From their comments further changes were made. The decision to release a version of the DM-ID abridged for easy use by clinicians grew out of feedback from the peer reviewers. An Advisory Board (see list of Manual Advisory Board at front of book) was created to provide guidance, review and feedback. Thus, the Advisory Board acted as a further peer review process, which resulted in further changes and refinements to the chapters. The editors and authors revised several drafts of each chapter incorporating the suggestions made by the peer reviewers.

Terminology: Intellectual Disability (ID) versus Mental Retardation (MR)

The editors of this Manual recognize that the use of terms to describe individual differences in cognitive abilities is controversial. The DSM-IV-TR uses the term Mental Retardation to denote disabilities of this nature, but this term has fallen into disfavor in many areas. In much of Europe and Canada as well as in the United States, the term Intellectual Disability (ID) is used with increased frequency in some circles. In 2007, the American Association on Mental Retardation (AAMR) changed its name to the American Association on Intellectual and Other Developmental Disabilities (AAIDD). The Journal of Intellectual Disability Research (JIDR) was formally the Journal of Mental Deficiency Research. The President’s Committee on Mental Retardation (PCMR) has changed its name to the President’s Committee for Persons with Intellectual Disabilities (PCPID). Nonetheless, the term Mental Retardation is still used in some areas of the United States for insurance and billing purposes. To add to the confusion, the term Learning Disability is used in the United Kingdom and is synonymous with the terms Mental Retardation and Intellectual Disability.

There is a growing movement toward acceptance of the term Intellectual Disability (ID). To ensure consistency in this manual, the editors have chosen to use this term, recognizing that terms change over time. The editors hope this decision will advance the international usage of the term and influence the professional and consumer communities to further embrace the term Intellectual Disability.

Field Testing of the DM-ID

During the summer of 2006, field trials of the abridged DM-ID (Diagnostic Manual – Intellectual Disability: A Clinical Guide for Diagnosis of Mental Disorders in Persons with Intellectual Disability) were held to assess its clinical usefulness. A data set of nearly 900 subjects was obtained. Sixty one percent of these were male and thirty nine percent were female. The level of ID was divided fairly evenly between Mild, Moderate and Severe/Profound. Approximately 80 clinicians from eleven different countries (see list of Field Trial Participants at front of book) provided feedback on their experience using the DM-ID. Questions were asked such as whether the DM-ID enabled the clinician to come up with a more specific diagnosis than he or she would have arrived at with the DSM-IV-TR, whether the DM-ID was user friendly, and whether the DM-ID allowed the clinician to arrive at a psychiatric diagnosis that the clinician thought was appropriate for the patient among other survey questions.

A Research Committee has been organized to analyze the data and report the results. Preliminary results appear positive. Clinicians found that, with a significant number of subjects, the DM-ID allowed them to come up with a more specific diagnosis than they would have using only the DSM-IV-TR. With a majority of the subjects, the clinicians found the DM-ID to be user friendly and clinically useful, and, with an overwhelming majority of subjects, they indicated that the DM-ID allowed them to arrive at a psychiatric diagnosis that they think is appropriate for the individual being diagnosed.

The Field Trial Participants provided many insightful and useful comments. Some of these were incorporated into improvements of this edition of the DM-ID; others will contribute to a later revision when this book is re-issued.

In addition to aiding clinicians in their work with individuals with ID and coexisting mental health problems, the Editors hope the DM-ID will stimulate research.

Summary

The Diagnostic Manual – Intellectual Disability (DM-ID): A Textbook of Diagnosis of Mental Disorders in Persons with Intellectual Disability is designed to provide state-of-the-art knowledge of mental disorders and ID. It provides a series of chapters that corresponds closely to the DSM-IV-TR classification system, with specifically proposed adaptations of the existing criteria to make them apply to persons with dual diagnosis. The authors of the chapters were selected largely from among professionals who had made international contributions to the field of dual diagnosis. The DM-ID, therefore, represents a multicentered, multicultural, and multifaceted collaborative effort of many experts, an effort aimed at an improved understanding of mental disorders and their unique expressions in persons with ID.