H. Thompson Prout, Ph.D.
In the last twenty years, professionals in mental retardation and developmental disabilities have become increasingly aware of the importance of mental health issues and psychiatric disorders in working with our clients. We have seen the growth and development of the National Association for the Dually Diagnosis (NADD), recognition of the mental health issues of persons with mental retardation in major diagnostic manuals (DSM-IV, AAMR diagnosis and classification), and the establishment of professional outlets devoted to dual diagnosis (NADD Bulletin, Mental Health Aspects of Developmental Disabilities). Additionally, there has been a significant increase in research and scholarly contributions on dual diagnosis in both journals focusing on mental retardation/developmental disabilities/intellectual disabilities and in more general journals in psychiatry/psychology and related areas. Clearly, the concept of "dual diagnosis" is now well-established in the professional and research domains of developmental disabilities.
The dual diagnosis area, however, has largely focused on issues with adults. For example, in the two primary professional outlets that focus on dual diagnosis, The NADD Bulletin and Mental Health Aspects of Developmental Disabilities, the vast majority of articles focus on adult or general dual diagnosis issues. An informal review of the years 2002-2004 indicates that less than 10% of the articles have specific or major themes on child and adolescent issues. In the same time frame, the Journal of Clinical Child and Adolescent Psychology had no articles with a major focus on issues of children and adolescents with mental retardation. The Journal of the American Academy of Child and Adolescent Psychiatry fared somewhat better, relatively consistently publishing a number of articles about children or adolescents with mental retardation. However, the focus of these articles is relatively narrow, largely presenting studies on medication effectiveness or atypical case studies. Overall, it is apparent that mental health issues of children and adolescents with intellectual disabilities has garnered little attention in the professional and research literature.
This article posits that there needs to be increased professional emphasis on mental health issues of children and adolescents with intellectual disabilities. As with other areas of adult psychopathology and maladjustment, treatment and preventive interventions in childhood and adolescence may partially ameliorate more serve presentation in adulthood. The mental health needs of children and adolescents with mental retardation appear to parallel patterns seen with adult populations. Further, there are options for both assessment and therapeutic interventions with children and adolescents that appear to be underutilized. Additionally, comprehensive services in the schools appear to represent a "missed opportunity" for both assessment and intervention. The purpose of this article is to:
"Briefly review studies of incidence and prevalence of psychiatric/psychological disorders among children and adolescents with intellectual disabilities
"Discuss options for assessment of child/adolescent social-emotional issues.
"Briefly review an analysis of studies of effectiveness of psychotherapeutic interventions with children and adolescents with mental retardation.
"Discuss opportunities in the schools for assessment, intervention, and collaboration.
Incidence and Prevalence
It is well established that persons with mental retardation are more susceptible to psychiatric disorders than other populations. The Diagnostic and Statistical Manual IV-TR (DSM-IV-TR) of the American Psychiatric Association (2000) notes that persons with mental retardation are three to four times more likely to have a second co-morbid psychiatric disorder. The DSM-IV-TR does not delineate any specific child/adolescent issues with regard to this increased incidence. Similarly, Borthwick-Duffy's (1994) review of incidence studies documents this general tendency of higher incidence of psychiatric disorder in persons with mental retardation. Additionally, these studies also demonstrate that persons with mental retardation can experience a wide range of psychopathology. Further, there is evidence that persons with mental retardation receive less attention in the health care system. A report, Closing the Gap: A National Blueprint to Improve the Health of Persons with Mental Retardation, released at the U.S. Surgeon General's Conference on Health Disparities and Mental Retardation (2001), suggested that an inequity in the health care system exists: persons with mental retardation suffer more physical and mental problems but appear to receive inferior care. Thus, the report represents a "call-to-action" for both researchers and practitioners, suggesting that attention should be directed towards the needs of this population, as well as filling in the gaps of our knowledgebase. The report noted that persons with mental retardation are "invisible" in the data on health status. Specifically, the report called for action to enhance the visibility of health research with persons with mental retardation and to collect data on health status. However, this report also shows little differentiation of child/adolescent issues.
The majority of studies of psychopathology among persons with mental retardation have been conducted with adult populations (Borthwick-Duffy, 1994). Emerson (2003) recently noted that there have very few population based studies on the prevalence of psychiatric disorders among children and adolescents with mental retardation. Borthwick-Duffy reviewed studies up through the early 1990's. Considerable variance was noted across studies, but rates for children and adolescents with mental retardation ranged from 10%-61% depending on the diagnostic rubric with some studies using more generic indices of problem behaviors or behavioral or emotional disturbance. Dykens (2000), noting considerable variance in prevalence rates, has reviewed a number of theoretical perspectives relative to the increased risk of psychopathology for children with mental retardation. Dykens cited a range of 10%-70%, and indicates that there is limited research that helps us understand the higher risk of psychopathology for children with intellectual disability.
In a landmark study, Rutter, Graham, and Yule (1970) brought attention to the prevalence of psychopathology among children and adolescents with mental retardation. Researchers found rates of mental illness as high as 40% in a population of institutionalized young persons. More recent general incidence/ prevalence studies of psychiatric disorders among children and adolescents with mental retardation were reviewed. This review covered studies published in the last 15 years (1989-2004) and identified 16 studies that could be categorized as population, incidence/prevalence, or epidemiological studies, most published in the last 10 years (Dekker & Koot, 2003a; Dekker & Koot, 2003b; Dekker, Koot, van der Ende, & Verhulst, 2002; Emerson, 2003; Hardan & Sahl, 1997; Kapur, Reddy, Uma, Padma, & Shahul, 2002; Einfeld & Tonge, 1996a; Einfeld & Tonge, 1996b; Linna et al., 1999; Masi, Brovedani, Mucci, & Favilla, 2002; Perlmenter, Einfeld, Tonge, & Dempster, 1998; Sherrad, Tonge, & Einfield, 1997; Sherrad, Tonge, & Ozanne-Smith, 2002; Slone, Durrheim, Kaminer, & Lachman, 1999; Tonge & Einfeld, 2000; Tonge, Einfeld, Krupinksi, & Mackenzie, 1996). As with other literature, the literature continues to point to higher rates of disorder and problems with children and adolescents. Among the findings were higher general rates of prevalence of psychiatric disorders, higher rates of a range of specific disorders, increased rates of "risky" health/injury behaviors, higher rated internalizing and externalizing behaviors, and higher rates of disturbance in specialized or segregated settings. These more recent studies also show considerable variance due to definitional issues, but generally report incidence/prevalence rates from 25%-48%.
In these incidence/prevalence studies, it is noted that only one of these more general studies was conducted with a sample from the United States (Harlan & Sahl, 1997) or Canada. Seven studies were conducted with Australian participants, three with Netherlands participants, one study each from English, Italian, Finnish, Indian, and South African sites. Of note, the Harlan and Sahl study was conducted in a clinical setting in specialized program for children and adolescents with developmental disorders. It does not represent a population study, but reflects prevalence in a special clinical sample. Clearly, there is gap in contemporary knowledge of incidence and prevalence rates from research based in North America.
There have also been a variety of studies examining more specific symptomatology and issues. For example, several studies have focused on depression (e.g., Heiman, 1998, 2001; Manikan, Matson, Coe, & Hillman, 1995). As noted, Dykens (2000) has reviewed studies examining issues related to various syndromes. In the more general health area, Zacijek-Farber (1998) has noted that there was a paucity of information regarding the general health, mental health, and life style choices of adolescents with developmental disabilities. Furthermore, the limited research available generally focused on the management of conditions associated with one's disability and/or the range of health risks related to the disabling condition (Zacijek-Farber, 1998). Thyen, Sperner, Morfeld, Meyer, and Ravens-Sieberer (2003) have highlighted issues related to unmet health needs of children and adolescents with disabilities (including developmental disabilities) and the concomitant stressors on the families.
In the past, professionals faced with assessing social-emotional or behavioral status of children and adolescents with mental retardation had limited options in terms of formal assessment instruments. Currently, the professional essentially has two options. The first involves the use of instruments that are designed for typically developing children and adolescents. For the most part, these instruments have not included persons with mental retardation in their normative samples and may not have included an appropriate range of behaviors in their item pools. Therefore, the validity of these measures with children and adolescents with intellectual disabilities remains in question. General measures such as the Child Behavior Checklist and the Children's Depression Inventory have been shown to have some diagnostic utility (e.g., Dekker et al., 2002; Masi et al., 2002). The use of these general measures designed for typically developing children and adolescents, however, has not been fully supported. Embregts (2000) investigated the reliability of the Child Behavior Checklist (CBCL) with children adolescents and concluded that the CBCL "may not always represent a reliable method for identifying behavioral problems among children and adolescents with mild mental retardation." (p. 38). Embregts noted adequate test-retest reliability but attributed most of this conclusion to the lower inter-rater (i.e., informant) correlations. Embregt, however, did acknowledge that these lower correlations are not uncommon in cross-informant research. Miller and his colleagues (Miller, Fee, & Jones, 2004; Miller, Fee, & Netterville, 2004) investigated the psychometric properties of several ADHD rating scales with children with mental retardation. Across these studies, they found some variance across raters (e.g., parent vs. teacher informants) with teacher ratings generally yielded stronger indices in several domains of reliability. Most scales were judged to be marginally adequate in terms of inter-rater reliability. Miller and his colleagues also noted that this tended to diminish concurrent validity across raters.
Measures designed for typically developing children and adolescents have two major areas of cautions when used with younger persons with mental retardation. First, the norms typically have not included persons with mental retardation and the instruments were not intended for use with persons with developmental challenges. Second, informant based measures have been shown to have marginal cross-informant and/or cross-setting reliability/validity. While some research has questioned the value of these more general measures, the cross-informant/setting issues may not be unique to the assessment of persons with developmental problems. In their classic correlational meta-analytic review, Achenbach, McConaughy , and Howell (1987) found that correlations across informants in different settings were typically low. They attributed these lower than desired cross-informant ratings to setting and perspective differences (e.g., parent vs. teacher) rather than necessarily representing deficiencies in instruments. These cross-informant differences are often seen in a range of clinical assessment situations and may not be endemic to social-emotional assessment of children and adolescents with developmental problems. Caution should be exercised when including these more general assessments with children and adolescents with disabilities, but their use does not appear to be precluded. At this time, there are many more of these general instruments and they may have a role in diagnosis of co-morbid disorders.
Obviously, the more preferred option would be to use instruments specifically designed for and normed on children and adolescents with mental retardation. A full review of these instruments is beyond the scope of this article, but several instruments are available. Informant measures include the Reiss Scales for Children's Dual Diagnosis (Reiss, 1990), Developmental Behaviour Checklist (Einfeld & Tonge, 1992), and the Aberrant Behavior Checklist (Aman & Singh, 1994). These measures approach "problem behavior" and psychopathology from different perspectives and should be used in a multi-method, multi-informant approach (Dykens, 2000). The Emotional Problems Scales (Prout & Strohmer, 1991) offers self-report and informant versions for adolescents (and adults) in the mild mental retardation and borderline intelligence ranges. Where possible and diagnostically appropriate, it would appear that the checklists and scales specifically designed for individual with mental retardation represent the best choice for assessment. The four scales noted here all assess across several behavioral and emotional domains.
Given the apparent rates of psychopathology, it appears there should be increased use of measures of psychopathology, behavior, and social-emotional status of children and adolescents with mental retardation. A multi-informant (teachers, parents, aides, children/adolescents) approach with use of multiple methods is indicated. Instruments specifically designed for persons with disability appear to be the first choice, but instruments designed for typically developing children and adolescents may be cautiously utilized.
McCarthy and Boyd (2002) conducted a retrospective study with young British adults with intellectual disabilities who had significant histories of child and adolescence psychiatric and behavior disorders. These researchers also cite programmatic data indicating children with intellectual disabilities are more likely to receive services from general health practitioners, rather than traditional mental health sources utilized by their peers without intellectual disability. Their findings showed that almost two-thirds received no mental health care at any point during their transition of early adolescence to adulthood. Interestingly, those individuals who did access formal mental health services were relatively satisfied with those services.
The issue of the effectiveness of psychotherapy has been a controversial area in mental health for years (e.g., see Prout, Chard, Nowak-Drabik, and Johnson, 2000). Prout and Nowak-Drabik (2003) reviewed a wide variety of studies of psychotherapy with persons with mental retardation conducted over a thirty year period (1968-1998). Their approach included an "expert consensus" panel method that included ratings of both outcome (i.e., amount of change) and effectiveness/benefits. Ninety-two studies were evaluated by the panel and smaller number (N=9) of studies were assessed via more traditional meta-analysis. Their panel review results showed that psychotherapy with persons with mental retardation yields a moderate amount of change and is moderately effective or beneficial. They also concluded that these apparent effects and benefits can be demonstrated, to some degree, across age, level of mental retardation, technique, and theoretical approach. Effective therapeutic interventions can also be carried out in a variety of settings. The small meta-analysis was also consistent with the "moderate" levels of overall effectiveness. A closer analysis of the child/adolescent findings shows outcome and effectiveness ratings were generally comparable to those studies conducted primarily with adults. Twenty-four (26% of the 92) studies were conducted with children or adolescents. Of these 24 studies, 42% were conducted with children or adolescents identified as being in the mild range of mental retardation, with 58% identified as being in the moderate or lower below ranges. Individual and group interventions were equally represented, and there was a range of the theoretical bases for the interventions. In general, the child/adolescent research base did not look substantially different from the adult base. Prout and Nowak-Drabik noted that the overall finding of "moderate" levels of effectiveness and benefit suggested that psychotherapeutic interventions should be more frequently considered in treatment plans with persons with mental retardation. This implication of their findings would also appear to apply to the child/adolescent area.
Opportunities in the Schools
The issue of dual diagnosis is virtually absent from the school-based literature in school psychology, special education, and pupil personnel services. Also, of the more recent studies of incidence/prevalence, only three of the studies appeared to include teacher/school input as a variable, with only one study predominately using teacher/school input (Permenter et al., 1998). This is somewhat bewildering considering the incidence/prevalence rates and the fact that the school is the second (family being first) most important setting for children and adolescents. With the legal changes in special education dating to the 1970's, almost all children with intellectual disabilities are either served in the schools or are provided support for education by the public schools. More inclusive environments also make these children more visible and involved in regular education. Yet, the issue of secondary social-emotional problems or psychiatric disorders is rarely directly addressed in assessment or the planning of educational programs and interventions.
This author, in the course of professional and consulting work, frequently reviews school-based psychoeducational assessment reports (approximately 2,000 of these reports have been reviewed in the last five years) and individual education plans (IEPs) of children and adolescents with a variety of disabilities. Two observations from this work are noteworthy. First, assessment of children and adolescents with mental retardation in the schools rarely includes a specific focus on social-emotional issues. Some assessments will address general social skill deficits or observation of behaviors like time "on-task" or "off-task," but these assessments usually do not address more diagnosis-specific problems. Occasionally, evaluators will utilize an adaptive measure that addresses global maladaptive behavior, but there is rarely more specified or targeted assessment. Specific social-emotional measures are infrequently used, whether they are instruments designed for typically developing populations or instruments designed for use with children and adolescents with mental retardation. Second, there are few interventions included in educational plans that address social-emotional issues. Where interventions are included, there is a predominance of behaviorally-oriented interventions (e.g., increase on-task behavior) or generic social-skill programs. Specific interventions for emotional difficulties are infrequently delineated and counseling is rarely included as a related service.
No other community institution has more frequent or regular contact with children and adolescents with mental retardation than the schools. The schools have the best opportunity to intervene with children and adolescents with dual diagnoses. Yet, this appears to be a "missed opportunity" with most schools not recognizing their options in this area. Considering a conservative co-morbidity rate of 25%, this would indicate that at least one in four students with mental retardation presents with significant behavioral or emotional challenges. Formal assessment in the social-emotional area needs to be more routinely included in both initial and re-evaluation assessments of students whose primary educational disability is in the mental retardation area. Similarly, IEPs need to include more "mental health" oriented interventions with their students with mental retardation. Counseling should be a more widely used option in the related service area. Schools that have full-service school programs or have collaborative on-site services provided by community mental health providers should insure that their students with mental retardation have access to the full range of services offered in these programs.
Dual diagnosis issues with children and adolescents are an underdeveloped and, in some respects, a neglected area. While there has been relatively rapid growth in research and professional interest in adult issues, the child and adolescent area lags in both research and development of clinical options. This paper has briefly reviewed the status of this area and offers several conclusions.
"Prevalence/incidence data suggests that children and adolescents with mental retardation show higher rates of psychopathology than their typically developing peers. However, there are gaps in the research with regard to rates of specific disorders and in research conducted with North American populations.
"Assessment of children and adolescents with mental retardation should more routinely include foci on behavioral and social-emotional issues. Comprehensive assessments using multiple sources of data are indicated. Assessment options include cautious use of instruments designed for typically developing children and adolescents and a instruments specifically designed for use with children and adolescents with mental retardation.
"Similarly, therapeutic interventions should be routinely considered in overall treatment planning for children and adolescents with mental retardation. Evidence suggests moderate effects and benefits, and that child/adolescent consumers may not frequently be offered services. When they access services, they report satisfaction.
"The schools appear to represent a viable setting to address dual diagnosis issues. Routine psychoeducational assessment should more frequently include a social-emotional and behavioral component beyond observation and social skill domains, and education plans should more routinely include mental health interventions. Schools that have collaborative mental health services on-site should insure that their students with mental retardation have access to those services.
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(H. Thompson Prout, Ph.D. is a Professor in the Department of Educational and Counseling Psychology and Director of Research at the Human Development Institute at (UCEDD) at the University of Kentucky, Lexington, Kentucky. He may be contacted at email@example.com.)