Psychiatric Assessment of the Person
With Mental Retardation


As published in the Psychiatric Annals 27:3/March 1997

Dr Silka is Senior Psychiatrist, START Clinical Services, Danvers, Massachusetts. Dr Hauser is Clinical Instructor in Psychiatry Harvard Medical School; Assistant Clinical Professor Department of Psychiatry University of Connecticut School of Medicine; and Forensic Psychiatrist, Program in Psychiatry and the Law, Massachusetts Mental Health Center Address reprint requests to Mark J Hauser, MD, PD Box 222, Newtonville, MA 02160.

The psychiatrist who does not specialize in mental retardation and developmental disabilities typically has had little or no exposure in medical school or residency training to the special diagnostic and therapeutic issues posed by this population,1 yet many psychiatrists will be called on, at some time, to evaluate and treat individuals with mental retardation, often in crisis situations requiring emergency admissions or in inpatient facilities. It is essential, therefore, that psychiatrists acquire the basic tools needed for assessment and treatment planning at the interface of mental retardation and psychiatric disorders.

  The DSM-1V2 defines mental retardation as follows:

  1. Significantly subaverage intellectual functioning-ie, an IQ of approximately 70 or below.
  2. Deficits or impairments in adaptive functioning.
  3. Onset before age 18 years.

Levels of Severity
  Mental retardation is subdivided into levels of severity based on IQ and associated features (Table 1).

  Individuals with mental retardation represent 1% to 3% of the general population. Mental retardation is approximately 1.5 times more common in boys than in girls.
  Until recently, a significant proportion of individuals with mental retardation were cared for in residential facilities such as state-run training schools. Currently, however, the vast majority of the developmentally disabled live in the community and use community resources for treatment.

  Mental retardation is highly heterogeneous as to cause. More than 250 biologic causes are known, most of which can be grouped under the general categories of chromosomal abnormalities, other genetic factors, prenatal and perinatal factors (eg, anoxia), acquired childhood disorders, environmental factors (eg, lead),3and sociocultural factors.
  Knowing the cause in a particular case can sometimes provide important clues for understanding an individual's presentation; however, only approximately 25% of cases of mental retardation have a known biologic cause; in the remaining 75% of cases, the cause is unknown or is traceable to nonbiologic (eg, psychosocial) factors.

  It has been estimated that 40% to 70% of individuals with mental retardation have diagnosable psychiatric disorders.4 This subgroup of individuals, however, are not the only ones who come in contact with psychiatrists. Like anyone else, a developmentally disabled person may present with emotional, behavioral, interpersonal, or adjustment problems that do not constitute major psychiatric disorders but that may benefit nonetheless from psychiatric input. Psychiatrists should remember that in clinical settings they do not have the opportunity to see people with mental retardation living and working in the community in a normal, non-problematic manner. As a result, they often do not have a baseline with which to compare current functioning.
  Psychiatrists called on to evaluate and treat developmentally disabled individuals in either an emergency or inpatient setting need to be aware of special considerations that set this population apart. These considerations occur mainly in two areas: (1) working as part of a team with the patient's regular caregivers; and (2) characteristics of mental retardation that may confound the usual procedures for psychiatric diagnostic assessment and treatment planning.

Table 1
Levels of Severity of Mental Retardation
Levels       IQ       Precentage of Mentally Retarded Population
50-55 to 70
35-40 to 50-55
20-25 to 35-40

Relationships With Other Caregivers
  Psychiatric care of individuals with mental retardation is most effectively rendered when the psychiatrist uses an interdisciplinary team model.5 The psychiatrist must take into account not only the acute problem but also the patient's relationship to long-term caregivers. These professionals tend to be deeply involved in the life of the patient, who they care a great deal about and see as their "client." They will likely contribute critically important diagnostic information and play a crucial role in implementing the treatment plan.
  At the same time, referring caregivers sometimes distrust doctors and medications.4'6 This aversion may lead them to delay getting a consultation until they are "at the end of their rope" and feel as if they can no longer cope with the patient, whose condition may have worsened in the interim. They may simultaneously harbor unrealistic expectations, such as that the psychiatrist will be a magical rescuer. This ambivalence can have disruptive consequences. A successful treatment outcome may depend in part on how well the psychiatrist can bridge the gap between different conceptual models (medical versus habilitative), clinical languages, and organizational styles.

Special Diagnostic Issues
  Mental retardation may obscure the standard diagnostic indicators of psychiatric disorders. For one thing, especially for the psychiatrist unaccustomed to the normal manifestations of mental retardation, those manifestations may overshadow symptoms attributable to psychiatric illness.7 Moreover, impairments in cognitive and verbal skills make it difficult for many developmentally disabled individuals to articulate abstract or global concepts such as a depressed mood. Most DSM-IV diagnoses require that the patient describe his or her internal state. Asking a person with an IQ below 40 about hallucinations, delusions, or guilt is seldom productive. On the other hand, the person's disorganized behavior may have diagnostic significance.8
  These are the challenges that people with mental retardation often pose for psychiatric diagnosis. Sovner 9 identified four aspects of mental retardation that may influence diagnosis:

  1. Intellectual distortion - emotional symptoms are difficult to elicit because of deficits in abstract thinking and in receptive and expressive language skills.
  2. Psychosocial masking - limited social experiences can influence the content of psychiatric symptoms (eg, mania presenting as a belief that one can drive a car).
  3. Cognitive disintegration - decreased ability to tolerate stress, leading to anxiety-induced decompensation (sometimes misinterpreted as psychosis).
  4. Baseline exaggeration - increase in severity or frequency of chronic maladaptive behavior after onset of psychiatric illness.

 To allow for these possible distortions, Sovner9 proposed that the standard diagnoses for mania and depression be modified, when applied to the developmentally disabled, to focus on biologic signs and symptoms and behavioral equivalents to subjective states.

  In a crisis, the emergency room can serve as a safe holding environment, a place for acute stabilization, emergency sedation, medical and psychiatric evaluation, and disposition for further treatment. When approaching a developmentally disabled person and his or her regular caregivers in a crisis situation, following certain basic principles helps set the stage for a less stressful, more nurturant, and more accurate evaluation. Some of these guidelines are equally applicable to the assessment of the developmentally disabled person in a more stable inpatient or outpatient situation.

  The most common categories of acute presentations in individuals with mental retardation are:

  1. New onset or escalation of aggression, self-injurious behavior, or both
  2. Changes in mental status, such as:
  3. Medication side effects, especially extrapyramidal symptoms
  4. Physical complaints or behavioral manifestations that might signify physical illness

  Of these, the most frequent cause of acute emergency presentations is aggression or self-injurious behavior. Most individuals with mental retardation do not display this kind of behavior. In those who do, it is not necessarily an indicator of psychiatric illness. Rather, when verbal expression is impaired, distress resulting from many possible causes may be expressed through maladaptive behavior such as aggression and self-injurious behavior. Such behavior may be seen as a final common pathway for various medical, psychiatric, interpersonal, and environmental circumstances. A diagnostic evaluation is therefore required.

Adaptive Functions
  Lowry and Sovner10 describe four functions of problem behavior that should be considered in any evaluation:

  1. Socioenvironmental control. Aggression and self-injurious behavior can be reinforced (ie, removing a person from an unpleasant situation in response to such behavior will increase the probability that the person will react similarly in the future).
  2. Communication. Problem behaviors can be a nonverbal means of communicating a variety of messages (attention, discomfort, needs).11
  3. Modulation of physical discomfort. Medical conditions, including medication side effects, can cause physical discomfort leading to aggression or self-injurious behavior.
  4. Modulation of emotional discomfort. Problem behaviors can occur as a state-dependent function of such disorders as major depression or bipolar disorder, manic phase.12

Evaluation and Treatment Strategies
  Lowry and Sovner10 have proposed a four-part strategy for evaluating and treating problem behaviors:

Differential Diagnosis
  When possible, treatment should be directed at the medical illness, psychiatric disorder, or other underlying cause of the maladaptive behavior. Table 2 shows a differential diagnosis for aggression, with the appropriate treatment linked to the cause of the aggression.

Differential Diagnosis of Aggression and Possible Treatments
Formulation Interventions
Aggression reflects medical illness.

Aggression reflects medication side effect.
Aggression reflects preseizure irritability.

Aggression reflects irritability secondary to
mania, depression, or organic mood disorder.

Aggression represents rage attacks.
Aggression is associated with task-related anxiety.
Aggression is associated with schizophrenia-related paranoid delusion.
Aggression is associated with inability to express needs.
Aggression is a means for obtaining positive reinforcers.
Aggression represents escape or avoidance behavior in the absence of an underlying dysfunction.

Have medical team assess and treat medical condition.
Teach client to request medical care.
Have medical team discontinue and/or substitute medication.
Have medical team review anticonvulsant regimen to establish better seizure control.
Treat with disorder-concordant drug, such as lithium for mania, fluoxetine for depression, or carbamazepine for organic mental syndrome.
Teach patient anger management skills.
Treat with propranolol or another centrally acting beta blocker.
Teach cognitive-behavioral skills to decrease anxiety.
Prescribe an anti-anxiety agent such as buspirone.
Treat psychosis.

Teach functional communication skills.

Enhance access to positive reinforcers. Teach socially acceptable, alternative behaviors.
Adapt environment to minimize aversive stimuli (eg, over-crowding). Teach appropriate escape behavior.

Source: Pary RJ, Silka VR, Blaha SJ. Mental retardation. In: Thienhaus OJ, ed. Manual of Clinical Hospital Psychiatry Washington, DC: American Psychiatric Press; 1995:287-309.

Symptomatic Treatment
  Treatment of aggression and self-injurious behavior secondary to mood disorders or psychotic disorders has met with some success. Because it is not always possible to diagnose the underlying psychiatric disorder or other cause, a symptomatic approach is sometimes necessary. Symptomatic treatments for aggression and self-injurious behavior include beta blockers, particularly for individuals with rage attacks or chronic states of overarousal13; buspirone when significant anxiety is present14; mood stabilizers such as lithium and carbamazepine when irritability exists15; neuroleptics16; opiate antagonists, such as naltrexone, especially in autism17; and selective serotonin reuptake inhibitors, such as fluoxetine, especially when the aggression is impulsive.18

  On the basis of the emergency evaluation, any of the following dispositions may be agreed on:

  Changes in the legal, institutional, and financial structure of psychiatric care have set a higher threshold for inpatient hospitalization. As in the general population, hospitalization is clearly indicated when a person poses an imminent danger to self or others because of a psychiatric illness. Hospitalization may also be indicated when outpatient treatment has been unsuccessful in halting a psychiatric decompensation or when a psychiatric illness has progressed to the point that the person is no longer able to function in the community. It is becoming increasingly difficult to obtain hospitalization for extended medication trials or for initial monitoring of a new course of pharmacologic treatment, despite that hospitalization may be appropriate in some such situations. Finally, Sovner and Hurley19 make clear that inpatient staff should not be expected to assume responsibility for the treatment of long-standing maladaptive behavior and to discharge a patient only after that behavior has remitted.

  The components of the assessment are described here for an inpatient evaluation, but most can also be performed in an outpatient setting.

  A thorough history, crucial for a psychiatric diagnosis, can be obtained from three sources: the patient, other informants, and medical records.
  The following guidelines are useful for interviewing the patient with mental retardation:

  Informants such as the family, case manager, or staff from the day program, worksite, or living site can provide information unobtainable from the patient directly. It is helpful to empathize with the informant's experience in caring for or working with developmentally disabled people and to educate the staff or family about what data are salient. Specifically, the following areas can be fruitful to explore:   Patient records, if available, should be reviewed for the following information, with emphasis on the annual assessment:

Behavioral Data
  Longitudinal behavioral data, when correlated with concurrent events such as environmental stresses, medical problems, and changes in medications, can contribute significantly to diagnosis and treatment. If possible, identify target behaviors that are symptoms of the (known or suspected) underlying psychiatric disorder and may be drug responsive, such as sleep disturbance in major depression. Establish baseline rates of the target behavior(s) to monitor response to treatment. A behavioral psychologist can help design, monitor, and educate the staff about data collection.

Mental Status Examination
  The mental status examination is an essential step in differentiating psychiatric from medical or situational problems. As modified for individuals at lower levels of functioning, it may include the person's general appearance; relationship to the examiner and others in the room; level and fluctuation of consciousness; psychomotor retardation or agitation; mood; range and appropriateness of affect; ability to communicate; ability to follow simple commands; visuospatial memory; orientation; and any observed abnormal involuntary movements, tremors, stereotypies, automatisms, or self-injurious behavior.
  When longer hospital stays were the rule, various rating scales and assessment tools were developed for persons with mental retardation.24'25 Although their use has been greatly curtailed by limitations on inpatient stays, situations may still arise in which such instruments can be employed feasibly.

Physical Examination and Diagnostic Studies
  A thorough medical evaluation is needed to rule out an organic cause of a change in mental status or maladaptive behavior. This aspect of the assessment is especially important because people with mental retardation have an elevated rate of associated physical disabilities. The physical examination must be performed systematically and patiently. Occasionally, when the individual is uncooperative and organic pathology is strongly suspected, sedation may be necessary.
  The evaluation resembles that performed to identify the causes of delirium and dementia in a geriatric population. Routine laboratory work consists of an EKG, measurement of electrolyte levels, a complete blood count, screening blood chemistry, urinalysis, measurement of folate and B-12 levels, syphilis serology, and thyroid function tests. Depending on the differential diagnosis, other laboratory tests may include an EEG, a brain imaging scan such as CT or MRI, and blood level measurements, especially of anticonvulsants.
  Drug interactions and medication side effects must also be considered.

  As part of the interdisciplinary team approach, the scope of the evaluation may be broadened to include, as needed, consultations with the disciplines of internal medicine, gynecology, neurology and behavioral neurology, neuropsychology, pharmacology, hearing and speech therapy,19 physical therapy, occupational therapy, and leisure skills therapy.

  The treatment plan should:

Psychopharmacologic Treatment
  The use of medications should be reserved for appropriate target disorders and syndromes. Medications should not be administered to the patient simply as a response to staff anxiety. To avoid this common pitfall, the psychiatrist may need to confront staff expectations skillfully, explaining that although "we all would want to have a medication that would treat the symptoms without side effects," such a medication does not exist. Emphasizing the possible environmental causes of problem behaviors can also help reduce the demand for indiscriminate prescription of medications.
  When antipsychotic drugs are used for non-specific sedation, the danger is that their use will be continued indefinitely, resulting in preventable side effects. Short-term administration of a benzodiazepine is a better choice for nonspecific sedation. Of course, medications may be needed for longer-term treatment of depression, bipolar disorder, psychotic disorders, obsessive-compulsive disorder, or attention deficit disorder. In addition, short-term pharmacologic treatment may be useful when certain symptoms have not responded to environmental interventions.26 Among these symptoms are the following:

  In these circumstances, medications should be prescribed with essentially the same indications, contraindications, precautions, doses, and monitoring as in the general psychiatric population but with special attention to possible behavioral effects in those with mental retardation.

  Appropriate acute or short-term inpatient treatment, coupled with long-term treatment recommendations, has the purpose of returning the individual to his or her prior environment or other suitable community setting. Effective discharge planning often strengthens the supports provided by an existing placement even as it facilitates continued psychiatric care. Most patients have an existing caretaking system to which they can return. To prevent the psychiatric unit from becoming a long-term residential facility for difficult clients, the referring agency should guarantee in writing a placement after discharge.19
 Ideally, discharge planning, including plans for outpatient follow up and the provision of any additional services, should begin at the initial treatment planning meeting or even before admission. Communication is the key to effective planning. Early and continual contact with all community supports, from family to outpatient therapists, is imperative. Questions to be addressed include the following:

  This focus will help hospital staff propose realistic aftercare treatment plans based on available resources and provider capabilities. The initial meeting may also identify a liaison who can smooth the transition between hospital and community.
  The patient, when stable, should be given a therapeutic pass to his or her home or day program. This transitional step not only tests the resilience of clinical improvement but also lets the patient see that he or she still has a room and a job available.
  Before discharge, a conference should be held to articulate a shared understanding about future treatment planning. The psychiatrist and hospital staff should see that the following points are covered:   The special case of discharge planning for the adult with mental retardation who can no longer be cared for at home by relatives (such as elderly parents) is dealt with elsewhere.27

  The psychiatrist should be aware of several important legal considerations.28

Informed Consent
  The diagnosis of mental retardation does not by itself imply that the individual is incompetent to consent to treatment. Competence must be assessed on a case-by-case basis. An individual who appears to understand the benefits, risks, and alternatives to psychiatric hospitalization should be given the opportunity to sign in voluntarily, unless a guardian has been appointed by the court. In an emergency setting, life-threatening problems warrant emergency treatment, even in the absence of informed consent. If someone is clearly not competent, a long-term caregiver or family member should be asked to consent to the evaluation and treatment.

  In cases where competence is impaired, guardianship may already have been established or may need to be considered. When a legal guardian has been appointed, authorization for evaluation and treatment must be obtained from the guardian, except in life-threatening emergencies.

Mandated Reporting of Abuse of Disabled Persons
  Many states have statutes that require medical personnel to report any suspicion of abuse.

Consent Decrees
  Many states have entered into binding legal agreements as a result of lawsuits initiated by plaintiffs to improve the quality of care delivered to people with mental retardation. These consent decrees may mandate procedural safeguards and specific measures of quality of treatment.

  The authors are indebeted to Archie Brodsky for his help with the manuscript.


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