The prevalence of psychiatric illness among people with mental retardation is estimated to be three to four times greater than that in the general population (1). However, the diagnosis of psychiatric disorders can be difficult due to the variability of behaviors and impaired communication skills of mentally retarded persons.
This paper presents the case of a patient with mental retardation and possible panic disorder and offers guidelines for screening for panic disorder among patients with mental retardation. The patient was seen by an emergency psychiatric service and mobile crisis program, which is a collaborative program of the Charleston Dorchester Community Mental Health Center and the department of psychiatry at the Medical University of South Carolina in Charleston.
Ms. X was initially brought to the attention of the emergency psychiatric service in June 1990 at age 58. She had mild mental retardation (an IQ of 56) and was experiencing new-onset paranoid delusions and auditory hallucinations precipitated by the death of her long-time caregiver. She was given a diagnosis of major depressive episode with psychotic features and was admitted to inpatient psychiatric care three times in the next six months. Each time she was discharged back to her own home, where she now lived alone.
After the depression remitted, she occasionally called 911 for emergency medical service with the vague complaint of "I feel bad." Emergency medical service personnel would routinely transport her to the local general medical emergency department, where she was often given intramuscular haloperidol and then discharged.
Over the next three years, Ms. X developed frequent somatic complaints, including chest pain, shortness of breath, and gastrointestinal distress, and fear. At times she would not leave her home—or even her room—for days or even weeks. Although she was unable to read or tell time, she called the emergency medical service more frequently, and at times she threatened to commit suicide if she were not brought to the emergency department. She persisted with chief complaints of "I feel bad," "I need to go to the hospital," or "I'll suicide." However, she never harmed herself. When she was evaluated by the psychiatric consultants in the emergency department, she denied depressed mood or neurovegetative symptoms of depression.
Emergency medical service records revealed that Ms. X had made up to 40 calls to 911 in one year and that her calls had resulted in total charges of $6,396 in 36 months. In almost all instances, emergency clinicians could find no medical condition, although they sometimes recorded a diagnosis of heat exhaustion or mental retardation.
The department of psychiatry's emergency service and mobile crisis program began to visit Ms. X, usually prompted by requests from the emergency medical service or from attending physicians in the emergency department after a series of 911 calls.
During 1993 we conducted a research study in which all adult patients seen by the psychiatric emergency service were administered a questionnaire on panic symptoms that was adapted from the Structured Clinical Interview for DSM-III-R (SCID). The questionnaire was given five times to Ms. X, who was seen in consultation four times for suicidal ideation and once for somatic symptoms. Ratings on the initial two questionnaires were inconsistent. She was unable to complete the third due to anxiety and dysphoria. However, her answers to the fourth and fifth questionnaires suggested that she had experienced eight of 13 symptoms associated with a DSM-III-R diagnosis of panic disorder.
In November 1993 a psychiatrist associated with the psychiatric emergency service prescribed clonazepam .5 mg twice a day. Records showed that Ms. X had less contact with all emergency services after that time. Ms. X's outpatient psychiatrist, who had been treating her since June 1990, added nortriptyline and soon documented a marked decrease in her symptoms of anxiety and panic.
Ms. X called the emergency medical service several times in late February and early March 1994, which led to a hospital admission for hyponatremia of unknown etiology. Her serum sodium level ranged from 115 to 120 mEq/L early in the admission. As nortriptyline may have contributed to her hyponatremia, her medication was changed to paroxetine 20 mg a day. The hyponatremia resolved.
Until a diagnosis of panic disorder was considered, emergency physicians and Ms. X's outpatient psychiatrist had treated her symptoms of dysphoria and anxiety by increasing doses of neuroleptics. She had been taking loxapine for many years. After her panic symptoms were identified, she was tapered off loxapine with no recurrence of psychotic symptoms. As of June 1994, Ms. X had little contact with the emergency medical service. She was stabilized on paroxetine and clonazepam and was free of panic symptoms.
People with mental retardation can develop the entire range of psychiatric disorders (2,3); estimates of the prevalence of psychiatric disorders in this population have ranged from 10 to 100 percent (4). One study estimated the prevalence at 15.5 percent, with a .63 percent prevalence rate for anxiety disorder (5). Youths with intellectual disabilities may report greater levels of fearfulness and a wider range of fears than those without such disabilities (6). Yet data on the comorbidity of anxiety disorders among these patients are limited (7).
Ms. X's presentation was unusual because her complaints lacked specificity. Given her level of cognitive functioning, she was unable to communicate effectively the level of anxiety associated with her dysphoria or somatic symptoms. The emergency medical and psychiatric personnel and even her outpatient psychiatrist did not understand her chief complaints as being secondary to the fear that panic attacks can produce. Panic disorder was never considered until it was screened for through a structured questionnaire. In retrospect, panic attacks may have precipitated Ms. X's calls to the emergency medical services, her visits to the emergency department, her fears about returning home, and possibly even her suicidal ideation.
Patients with panic attacks are more likely to seek care at general physicians' offices or emergency rooms than at mental health care facilities (8). However, physicians do not routinely perform evaluations using the SCID in primary care or emergency settings. In our year-long study of panic among adults treated by our psychiatric emergency service, about 13 percent of patients who needed psychiatric emergency intervention met criteria for a lifetime history of panic attacks or panic disorder (Zealberg JJ, Hardesty SJ, Dias JK, et al., unpublished data, 1994). Most presented with other axis I or axis II disorders; panic was rarely the primary reason for the emergency visit.
The following guidelines for identifying anxiety disorders among patients with mental retardation are offered to primary care and emergency physicians and to psychiatrists consulting in these settings. When assessing patients with mental retardation, clinicians should pay close attention to avoidant and possibly agoraphobic behaviors, particularly if they represent a change from previous behavior patterns. Vague, inconsistent, or multiple somatic complaints, especially those leading to repeated visits to doctors' offices or the emergency department, should alert practitioners to consider psychiatric etiologies such as panic. Clinicians should be aware that anxiety could lead a patient with mental retardation to refuse to leave the office or emergency department or even to express vague suicidal ideation.
A structured, simplified format for assessing psychiatric disorders may lead to more accurate diagnosis. Concern about using unmodified DSM diagnostic criteria with patients with mental retardation has been discussed in the literature, as has the need to adapt such criteria for use with this population (9). The questionnaire we used in screening for panic disorder was based on the SCID for DSM-III-R; similar screening tools could easily be adapted from the SCID for DSM-IV.
Accurate diagnosis of psychiatric disorders among people with mental retardation will result in more effective treatment, possibly with fewer adverse effects. In the case of Ms. X, antipsychotic agents had been prescribed. Once panic was considered, her condition responded much better to therapy with a selective serotonin reuptake inhibitor and a benzodiazepine. These medications also had the advantage of decreasing the risk of extrapyramidal symptoms and tardive dyskinesia. Ms. X became able to shop, visit friends, and perform other tasks of daily life, without calls to the emergency medical service and costly visits to the emergency department.
Dr. Malloy is a psychiatric resident, Dr. Zealberg is associate professor, and Dr. Paolone is clinical instructor in the department of psychiatry and behavioral sciences at the Medical University of South Carolina, 171 Ashley Avenue, Charleston, South Carolina 29425. Dr. Zealberg and Dr. Paolone are also with the Charleston Dorchester Community Mental Health Center in Charleston.