DM-ID Clinical Guide
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
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.
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 persons 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
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
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 individuals 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
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
groupsfor the medically ill and for geriatric patients among
others, as well as those for childrenno 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.
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 others 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
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 Presidents Committee on Mental
Retardation (PCMR) has changed its name to the Presidents
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.
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.