Information on Dual Diagnosis
The mental health needs of persons with intellectual or developmental disabilities have been increasingly recognized in recent years. In this section, we will define some terms and point out pertinent information concerning mental health aspects of intellectual or developmental disabilities.
What is Dual Diagnosis?
Dual Diagnosis is a term applied to the co-existence of the symptoms of both intellectual or developmental disabilities and mental health problems. We will clarify the meaning of dual diagnosis in the paragraphs that follow.
Intellectual or developmental disabilities:
The American Psychiatric Association defined intellectual disabilities as significantly below average intellectual and adaptive functioning with onset before age 18 years (DSM-IV-TR, 2000). General intellectual functioning is measured by an individually administered standardized test of intelligence that results in an overall intelligence quotient (IQ) for the individual Significantly subaverage functioning is defined as an IQ score of 70 or below. Adaptive behavior refers to the effectiveness with which an individual meets society’s demands of daily living for individuals of his/her age and cultural group. The measurement of adaptive behavior may include an evaluation of an individual’s skills in such areas as eating and dressing, communication, socialization and responsibility.
DSM-IV-TR’s Four degrees of severity are solely related to the individual’s level of intellectual impairment:
Mild, Moderate, Severe and Profound:
Mild Intellectual Disabilities: IQ level 50-55 to approximately 70
Moderate Intellectual Disabilities: IQ level 35-40 to 50-55
Severe Intellectual Disabilities: IQ level 20-25 to 35-40
Profound Intellectual Disabilities: IQ level below 20 or 25
The definition, classification, and systems of supports Manual of the American Association on Mental Retardation (AAMR; Luckasson et al., 2002) includes the same three diagnostic criteria (i.e., significant limitations in intellectual functioning, significant limitations in adaptive functioning, and onset prior to age 18 years). In the AAMR System, the criterion of significantly subaverage intellectual functioning refers to a normative score that is at least 2 standard deviations below the population mean.. Furthermore, DSM-IV-TR specifies levels of severity of intellectual disabilities, whereas the AAMR 2002 System specifies that intellectual disabilities is present or not. The AAMR 2002 System encourages the use of its multidimensional classification system that includes: level of intellectual functioning limitations (mild, moderate, severe, profound), levels of adaptive behavior limitations (mild, moderate, severe, profound), intensity of support needs (intermittent, limited, extensive and pervasive), etiology, etc. Luckasson et al., (2002) discourages the classification of the condition of intellectual disabilities based solely on individual’s severity of intellectual deficits.
The definition of Developmental Disabilities in Public Law 106-402 (2000) is not limited to Intellectual disabilities and is based on functional criteria. The Developmental Disabilities Act defines the term developmental disability as a severe, chronic disability of an individual that:
(I) is attributable to a mental or physical impairment or combination of mental and physical impairments;
(II) is manifested before the individual attains age 22;
(III) is likely to continue indefinitely;
(IV) results in substantial functional limitations in 3 or more of the following areas of major life activity:
(ii) Receptive and expressive language.
(vi) Capacity for independent living.
(vii) Economic self-sufficiency; and
(V) reflects the individual’s need for a combination and sequence of special, interdisciplinary, or generic services, individualized supports, or other forms of assistance that are of lifelong or extended duration and are individually planned and coordinated.
Mental Health Problems:
Mental health problems are severe disturbances in behavior, mood, thought processes and/or interpersonal relationships. The Diagnostic and Statistical Manual of Mental Disorders (DSM IV-TR, 2000) lists the different types of mental disorders.
The types of psychiatric disorders persons with intellectual or developmental disabilities experience are the same as those seen in the general population, although the individual’s life circumstances or level of intellectual functioning may alter the appearance of the symptoms. Some of the common types are:
Mood Disorders: The disorders are characterized by disturbance of mood as a predominant feature. Depression, bi-polar and mania are the major sub-categories of mood disorders.
Anxiety Disorders: This group of disorders is indicated by the presence of excessive fears, frequent somatic complaints and excessive nervousness that can interfere with functioning. Panic attack, agoraphobia, obsessive-compulsive and post traumatic stress disorder are some of the major sub-categories of anxiety disorders.
Psychotic Disorders: This group of disorders is characterized by any of the following signs and symptoms: delusions, hallucinations, disorganized behavior and impairment in reality testing. Schizophrenia, schizoaffective disorder and schizophreniform are some of the major sub-categories of psychotic disorders.
Personality Disorders: The group of disorders refers to enduring patterns of dysfunctional behavior. Symptoms typically present as personality traits that are inflexible, maladaptive and cause significant impairment or subjective distress. Paranoid, anti-social, borderline and avoidant are some of the major sub-categories of personality disorders.
Adjustment Disorders: The essential feature of these disorders is the development of clinically significant emotional or behavioral symptoms in response to an identifiable psychosocial stressor(s). The clinical significance of the reaction is indicated by either marked distress that is beyond that which is expected or by impairment in social or occupations functioning. Sub categories of adjustment disorders include adjustment disorder with depressed mood, with anxiety, with disturbance of conduct and with mixed disturbance of emotions and conduct.
Other psychiatric disorders include: somatoform disorders, factitious disorders, dissociative disorders, sexual and gender identity disorders, eating disorders, sleep disorders, substance abuse related disorders, impulse control disorders, dementia disorders, dissociative disorders, and disorders usually first diagnosed in infancy, childhood or adolescence.
Mental Health Aspects of Intellectual and Developmental Disabilities:
Persons with a dual diagnosis can be found at all ages and levels of intellectual and adaptive functioning. Estimates of the frequency of dual diagnosis vary widely, however, many professionals have adopted the estimate that 30-35% of all persons with intellectual or developmental disabilities have a psychiatric disorder. The full range of psychopathology that exists in the general population also can co-exist in persons who have intellectual or developmental disabilities.
The co-existence of intellectual or developmental disabilities and a psychiatric disorder can have serious effects on the person’s daily functioning by interfering with educational and vocational activities, by jeopardizing residential placements, and by disrupting family and peer relationships. In short, the presence of behavioral and emotional problems can greatly reduce the quality of life of persons with intellectual or developmental disabilities. It is thus imperative that accurate diagnosis and appropriate treatment be obtained in a timely manner.
Why So Prevalent?
The causes of the increased vulnerability to mental health problems in persons with intellectual or developmental disabilities are not well understood. Several factors have been suggested. Stress is a risk factor for mental health problems. Persons with intellectual or developmental disabilities experience negative social conditions throughout the life span that contribute to excessive stress. These negative social conditions include social rejection, stigmatization, and the lack of acceptance in general. Social support and coping skills can buffer the effect of stress on mental health. In persons with intellectual or developmental disabilities, limited coping skills associated with language difficulty, inadequate social supports, and a high frequency of central nervous system impairment, all contribute to the vulnerability of developing mental health problems. Another explanation for the increased prevalence of mental health problems in this population relates to behavioral phenotypes. In addition to the characteristic physiological signs associated with genetic syndromes, many syndromes have characteristic behavior and emotional patterns. These behavioral phenotypes may contribute to the increased rate of behavioral and mental health problems among persons with intellectual or developmental disabilities.
Is This a New Phenomenon?
The identification of psychiatric disorders in persons with intellectual and developmental disabilities is not a new phenomenon, but it has received much more attention in recent years. The process of deinstitutionalization, by which many individuals with intellectual and developmental disabilities were released from institutions and placed in community residences, has increased the visibility of dual diagnosis. Although psychiatric disorders have been observed in persons with intellectual and developmental disabilities for many years, there have been impediments to more widespread professional recognition of dual diagnosis. One obstacle is “Diagnostic Overshadowing” which occurs when a diagnostician overlooks or minimizes the signs of psychiatric disturbance in a person with intellectual disabilities. The psychiatric disorder may be overlooked because it is considered less debilitating than intellectual disability or because it is thought to be a result of intellectual deficits. Professionals who are pressed to assign a “primary” diagnosis may focus on intellectual functioning, ignoring the psychiatric problem.
Another impediment to the recognition of mental illness in persons with intellectual disabilities has been the tendency for the administration and funding of mental health and intellectual or developmental disability services to be separate. Each system may expect the other to serve the person with a dual diagnosis. In addition, staff at both types of agencies may feel ill equipped to provide adequate services. There is a great need to train qualified personnel in the diagnosis and treatment of psychiatric disorders among individuals with intellectual or developmental disabilities.
What Treatments are Available?
Most experts agree that treatment requires a comprehensive plan with several components. An interdisciplinary evaluation of the individual is necessary to obtain an accurate diagnosis and to establish habilitation and treatment needs. A thorough medical and neurological evaluation should be included to identify acute or chronic conditions that may need attention. A psychiatric evaluation can determine if medication is appropriate. Follow-up interviews are required to monitor the individual’s response to the various treatments.
Psychopharmacology: Medication treatment is appropriate for many psychiatric disorders(i.e., mood disorders and psychotic disorders). Medication treatment should not be a total treatment approach per se, but rather part of a comprehensive bio-psycho-social-developmental treatment approach.
Psychotherapy: Individual, group and/or family psychotherapy may be included in the treatment plan. Psychotherapists may draw techniques from many theoretical orientations, including behavioral, cognitive, cognitive-behavioral, gestalt, psychodynamic, nondirective, or systems. ,. Group therapies include skills training groups such as social skills, dating skills, assertiveness, and anger management training.
Other therapy groups may focus on specific developmental tasks such as independence or bereavement. The groups may be structured or unstructured, time-limited or ongoing. Verbal psychotherapies are most appropriate for persons with mild to moderate intellectual disabilities.
Behavioral Management: Behavior management plans are developed to deal with inappropriate behaviors and to teach adaptive skills. A functional analysis of behavior is conducted to determine the best approaches to use in the behavior plan. Systematic behavior programs may be implemented by individuals in the person’s environment. The person who is dually diagnosed may participate in the design of the behavioral program.
Many treatment modalities and approaches have been tried, with varying degrees of effectiveness, with persons with intellectual and developmental disabilities. Evidence-based treatment approaches are those that have been empirically tested and proven effective for persons with intellectual and developmental disabilities. It is considered best practice to use evidence-based treatments.
What Other Services might be needed?
Day Treatment: Day treatment, or partial hospitalization, programs for persons who are dually diagnosed have been established in many communities. The programs serve individuals with intellectual or developmental disabilities who have difficulty functioning in a traditional school or vocational program due to behavioral or psychiatric problems. Day treatment programs are generally designed for both rehabilitation and education, and include small group activities that focus on independent living skills, interpersonal skills, vocational preparation, and enrichment activities. Small group and individual psychotherapy are usually scheduled as part of the weekly program.
Social Skills Training: Social skills training is usually a time limited approach that helps persons to improve the quality of their life by enhancing interpersonal interactions. Individuals are taught effective and appropriate social behaviors.
Residential Services: Residential treatment programs have also been developed. These include inpatient units with intensive treatment programs for those individual who require 24-hour supervision in a secured environment. In community settings, a range of residential options is available, although the demand often exceeds the available supply. Community placements include group homes, foster care, and supervised apartments, as well as programs that provide in-home family services and respite care.
Crisis Intervention Services: Additional services may be called upon in emergency situations. These services are designed for short-term use to stabilize immediate crises. These services may include Assertive Community Treatment Teams, Crisis Homes, or short-term hospital admissions.
Other services provided to individuals with intellectual and developmental disabilities and mental health problems may include physical therapy, speech therapy, art therapy and occupational therapy, among others, depending on individual needs. The coordination of services is an essential task.
American Psychiatric Association (2000). Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Test Revision (DSM-IV-TR). Washington, DC: Author.
Luckasson, R., Borthwick-Duffy, S., Buntinx, W. H. E., Coulter, D. L., Craig, E. M., Schalock, R. L., Snell, M. E., Spitalnik, D. M., Spreat, S., & Tassé, M. J. (2002). Mental retardation: Definition, classification, and system of supports. Washington, DC: American Association on Mental Retardation
Developmental Disabilities Assistance and Bill of Rights Act of 2000. Public Law 106-402. October 30, 2000.
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