Pages Navigation Menu

Some Issues of Dual Diagnosis (1986)

Some Issues of Dual Diagnosis (1986)

©1986, 2013 by Dallas Denny

Source: Denny, Dallas. (1986). Persons who are mentally ill and mentally retarded: Some issues of dual diagnosis. Paper for Dr. Sid Levy, Department of Special Education, George Peabody College of Vanderbilt University.




Persons Who Are Mentally Ill and Mentally Retarded

Some Issues of Dual Diagnosis


By Dallas Denny

 For Dr. Sid Levy

Special Education 3936


April 21, 1986





Individuals who have been certified as mentally ill and mentally retarded are said to be “dual diagnosed.” Because there is a high rate of mental and emotional illness in retarded persons, there is a considerable population of dually-diagnosed individuals. This paper provides a brief discussion of policy, diagnostic, arid treatment issues of dually-diagnosed individuals. There is further discussion of one treatment issue, administration of psychotropic drugs in residential facilities for the mentally retarded as it relates to the policy of The Accreditation Council for Services for Mentally Retarded and other Developmentally Disabled Persons (ACMRDD).

In the United States, individuals who are considered to be mentally retarded fit the diagnostic criteria of the American Association on Mental Deficiency Manual on Terminology and Classification in Mental Retardation (Heber, 1959). This three-pronged definition requires that for diagnosis of mental retardation, an individual show (1) significantly subaverage general intellectual functioning.; and (2) concurrent deficits in adaptive behavior, which (3) are manifested during the developmental period (before the 18th birthday). The DSM-III, The Diagnostic and Statistical Manual of Mental Disorders (3rd Edition) of the American Psychiatric Association (1980) reflects the AAMD criteria for diagnosis of mental illness. The DSM-III allows concurrent diagnosis of a number of conditions which are traditionally called mental illness. Individuals who have been certified as mentally ill and mentally retarded are said to be “dually diagnosed.”

Certainly, mentally retarded persons may be also mentally ill. Rates of psychopathology in mentally retarded individuals may be much greater than in non-retarded individuals (Beier, 1964). After surveying studies of the incidence of mental illness in the mentally retarded, Lewis and MacLean (1982) concluded, “The available studies lead to the inescapable conclusion that emotional disorders are much more common among mentally persons than in the general population. This conclusion is based on investigations using very different patient samples and very different methodologies” (p. 7).

Reiss (1982) surveyed 66 referrals to a Developmental Disabilities Mental Health Program in the Chicago metropolitan area. He found that 51 of the 66 mentally retarded persons who were referred had one of four types of psychopathology: (1) schizophrenia or schizoid disorder, (2) antisocial behavior, (3) depression, or (4) personality disorder. The type and incidence of psychopathology, client age, and client sex were unremarkable; that is, the breakdown for these variables was about what would be expected in as many referrals of non-retarded individuals.

Kauffman (1985) has pointed out that mentally retarded and emotionally disturbed persons are very similar in their characteristics. It might be expected that the therapeutic needs of mentally ill mentally retarded persons would be very similar to the therapeutic needs of non-retarded mentally ill persons. It seems, however, that dual diagnosed persons comprise an underserved population (Reiss, 1982).

The presence of psychiatric symptomatology is a major factor in the institutionalization of mentally retarded persons (Russell and Tanguay, 1981), possibly because of limited opportunities for treatment in the community. Treatment opportunities may be limited because some professionals may see the emotional needs of retarded persons as unimportant or as secondary to their mental retardation (Philips, 1967). Matson (1981) sent a questionnaire to over 100 physicians throughout the United States. All of the physicians were given the mental symptoms of a young man and asked to make recommendations for treatment. Half of the questionnaires contained an additional sentence indicating that the man was mildly mentally retarded. The physicians who were not informed the man was retarded recommended a variety of treatments. The majority of the group of physicians who were informed the man was retarded attributed the emotional problems to the mental retardation and had no recommendations for treatment.

Shortly after the publication of the AAMD Manual on Terminology and Classification of Mental Retardation (Heber, 1959), there was an ongoing discussion in the pages of The American Journal of Mental Deficiency. The issue was whether the Manual enabled professionals to distinguish primary mental retardation with secondary emotional disturbance from primary emotional disturbance with secondary mental retardation.

Halpern (1972) has written about this debate. The debate was complicated and never satisfactorily resolved; however, some important issues were raised. One concerned the difficulty of determining whether mental retardation was the primary or secondary diagnosis. Intelligence and adaptive behavior can be negatively affected by many psychiatric conditions (Garfield and Wittson. 1980). A prime example of this is autism. DSM-III gives as diagnostic criteria:

1. Onset before 30 months of age.

2. Pervasive lack of responsiveness to others (autism).

3. Gross deficits in language development.

4. If speech is present, peculiar speech patterns such as immediate and delayed echolalia, metaphorical language. pronominal reversal.

5. Bizarre responses to various aspects of the environment, e.g. resistance to change. peculiar interest in or attachments to animate or inanimate objects.

6. Absence of delusions, hallucinations, loosening of associations, and incoherence as in schizophrenia (pp. 89-90)

The bizarre behavior and emotional aloofness of autistic children and adults often leads to severely decreased adaptive behavior and to severely decreased performance on standardized intelligence tests. This is exacerbated by the early onset of the condition (Chess, Korn, & Fernandez, 1971; Putter & Lockyer, 1967). Many autistic children meet the diagnostic AAMD criteria for mental retardation, and most professionals now acknowledge that many autistic children are mentally retarded (Lewis & MacLean, 1982; Tanguay, 1980). Yet in autism mental retardation is secondary to the emotional disturbance. With other emotional disorders, the diagnostic picture is more muddled, making it very difficult to determine whether emotional disturbance or mental retardation is the primary diagnosis. This problem is compounded with individuals who are severely and profoundly retarded, who may lack the language abilities to communicate symptoms of depression, delusions, or hallucinations.

Historically, there has been little distinction between the mentally ill and the mentally deficient (Kanner, 1964). Prior to the 1700s, the two conditions were not discriminated (Lewis & MacLean, 1982). Woolfson (1984) reported that the first reported Instance of an attempt to deal with mental retardation was in a textbook by Montaldo, which was published in 1614. By the nineteenth century, distinctions were generally drawn between mental retardation and mental illness (Kauffman, 1985).

In this country, services for the mentally retarded were initiated somewhat after services for the insane. For example, the establishment of asylums for the insane generally preceded by about a century the establishment of homes for the retarded. This was the case in Tennessee, where an asylum was in operation before 1800; what is now Clover Bottom Developmental Center was not built until the 1920s (Dokecki & Mashburn, 1984). What is now the Tennessee Department of Mental Health and Mental Retardation was until recently the Tennessee Department of Mental Health (Whitfield, 1976).

Treatment of the mentally retarded has come to be the domain of the fields of psychology and special education:

 The recent emphasis on mental retardation, which was heralded by the infusion of tremendous amounts of political and financial support in the 1960’s, has further delineated mental retardation as a self-contained biobehavioral condition, one separate from, the mainstream of mental health.

The dichotomization of services has resulted, in part, from the nature of mental retardation. Because the habilitation of mentally retarded individuals involves education and behavioral control, special education, psychology, and psychiatry have created their own regions of interest and influence in the habilitation process… psychiatry has been relatively uninvolved. p. 3.

Lewis and MacLean (1982) go on to point out that the insight-oriented psychodynamic approach frequently leaves something to be desired in the treatment of mental retardation. It could be that because retarded development is not a manifestation of an illness that can be cured, there is resistance among insight-oriented professionals to work with mentally retarded individuals” (p. 4).

We have seen that there are unresolved issues of diagnosis and treatment of dual diagnosed individuals. A brief discussion of one treatment mode should illustrate some of these problems more fully.

Since their introduction about 30 years ago, psychoactive drugs, especially the phenothiazine tranquilizers, have been given to large numbers of mentally retarded individuals. A number of researchers have found that the frequency of use of these drugs in institutions can exceed 50% of the population. For example, Lipman (1971) found a rate of 51%. Marker (1975) found a rate of 60% for psychotropic drugs in four Southern institutions. In both of these studies, the phenothiazine tranquilizers Thorazine (chlorpromazine) and Mellaril (thioridazine) were the most widely used drugs.

The phenothiazine tranquilizers were designed to benefit psychotic individuals and are of doubtful benefit with nonpsychotic individuals. The authors of a number of studies of the efficacy of psychotropic drug use with mentally retarded individuals have concluded that there is no evidence that the drugs are effective in controlling the behavior of mentally retarded persons; in general, the methodologies are so bad that the results are uninterpretable (Breuning & Poling, 1982).

Long-term, and sometimes even short-term administration of the phenothiazine tranquilizers has been shown to have irreversible side effects for many individuals (Gualtieri, Quade, Hicks, Mayo, & Shroeder, 1984). Yet the phenothiazines are widely and routinely used with severely and profoundly retarded individuals. The Accreditation Council for Services for Mentally Retarded and other Developmentally Disabled Persons (ACMRDD), which has provided standards for provision of services to handicapped individuals (Standards for Services for Developmentally Disabled Individuals, 1977), frowns upon indiscriminate use of these drugs: section includes explicit provision for gradual diminishing of dosage and ultimate discontinuation of the drug (which is used for behavior management) (p. 33). For institutions to become and remain ACMRDD accredited, plans must be made for each individual receiving psychotropic drugs to have the drugs gradually reduced to discontinuation. Most large, state-operated facilities for the mentally retarded strive for accreditation by ACMRDD, and future studies of the incidence of use of psychotropic drugs in such institutions may well reflect lowered rates of use.

The ACMRDD policy is a global one, however, and does not discriminate between those mentally retarded individuals who have been demonstrated to be mentally ill and individuals who have not been demonstrated to be mentally ill. Since the drugs have been demonstrated to be effective with mentally ill individuals, this ACMRDD policy may be unfair to those persons who are indeed psychotic. Considering that residents of mental hospitals don’t typically have these mandated reductions, psychotic severely and profoundly retarded individuals may be discriminated against by the ACMRDD policy.

There are other issues in the diagnosis and treatment of dual-diagopsed individuals. For example, should treatment occur at facilities for the mentally retarded, at facilities for the mentally ill, or at special facilities for dually diagnosed individuals? Who is responsible for these individuals? In Tennessee, there is a move toward treating dual-diagnosed individuals in special facilities (Dokecki & Mashburn, 1984). Effective treatment of mentally retarded and mentally ill individuals may require such a restructuring in service delivery systems (Lewis and MacLean, 1982).



Accreditation Council for Services for Mentally Retarded and Other Developmentally Disabled Persons. (1977). Standards for services for developmentally disabled individuals. Chicago, IL: Joint Commission on Accreditation of Hospitals.

American Psychiatric Association (1990). Diagnostic and statistical manual of mental disorders (3rd ed,). Washington, D.C.: American Psychiatric Association.

Beier, D.C. (1964). Behavioral disturbances in the mentally retarded. In Stevens, H.A. & Heber, P. (Eds.), Mental retardation. Chicago: University of Chicago Press.

Breuning, S.E.; & Poling, A.D. (1982). Pharmacotherapy. In Matson, S.E.; & Barrett, P. P. (Eds.) Psychopathology in the mentally retarded. New York: Crone & Stratton.

Chess, S.; Korn, S.J.; & Fernandez, P.B. (1971). Psychiatric disorders of children with congenital rubella. New York: Brunner/Mazel.

Dokecki, P.; & Mashburn, J. (1984). Beyond the asylum. Nashville: Tennessee State Printing Office.

Garfield, S.L,; & Wittson, C. (1960). Some reactions to the revised Manual on terminology and classification in mental retardation. American Journal of Mental Deficiency, 64, pp. 951-953.

Gualtieri, C.T.; Quade, D.; Hicks, P.E.; Mayo, J.P.; & Shroeder, S,R. (1984). Tardive dyskinesia and other clinical consequences of neuroleptic treatment in children and adolescents. American Journal of Psychiatry, 141(1), pp. 20-23.

Halpern, A.S. (1972). Some issues concerning the differential diagnosis of mental retardation and emotional disturbance. Mental Retardation, 4, pp. 796-800.

Heber, P. (1959). A manual on terminology and classification in mental retardation. American Journal of Mental Deficiency, 64 (Monogr. Suppl. 2).

Kanner, L. (1964). A history of the care and study of the mentally retarded. Springfield, IL: Thomas.

Kauffman, J.M. (1985). Characteristics of children’s behavior disorders (3rd Ed.). Columbus, OH: Charles E. Merrill Publishing Company.

Lewis, M.H.; & MacLean, W.E., Jr. (1982). Issues in treating emotional disorders, In Matson, J.L., Psychopathology in the mentally retarded. New York: Grune & Stratton.

Lipman, R.S. (1971). The use of psychopharmacological agents in residential facilities for the retarded. In: Menolascino (Ed.), Psychiatric approaches to mental retardation. New York: Basic Books.

Marker, C. (1975). Legal restrictions on the use of phenothiazines. Unpublished manuscript. (Available from the Mental Health Law Project, 1751 N. Street, N.W., Washington, D.C.20036).

Montaldo. (1614). Archipathologia. Cited in Woolfson, P.C. (1984), Historical perspective on mental retardation. American Journal of Mental Deficiency, 89(3), pp. 231-235.

Philips, I. (1967). Psychopathology and mental retardation. American Journal of Psychiatry, 124, pp. 1265-1271.

Reiss, S. (1982), Psychopathology and mental retardation: Survey of a developmental disabilities mental health program. Mental Retardation, 20(3), pp. 128-132.

Russell, A.T.; & Tanguay, P.E. (1981). Mental illness and mental retardation: Cause or coincidence? American Journal of Mental Deficiency, 5(6), pp. 570-574.