This special issue of International Psychogeriatrics, “Behavioral and Psychological Symptoms of Dementia: A Clinical and Research Update,” contains the proceedings of a conference held in Lansdowne, Virginia, May 11–13, 1999. It is a sequel to a previous issue that was based on the first international Consensus Conference on Behavioral Disturbances of Dementia (Lansdowne, Virginia, March 31–April 2, 1996). The rationale for the second conference was the growing interest in the symptoms of dementia (e.g., physical aggression, delusions, wandering) that result in premature institutionalization, emotional suffering for patients and caregivers, increased financial costs, and excess disability.

DIAGNOSIS AND ASSESSMENT

Behavioral and psychological symptoms of dementia (BPSD) can be defined as “a term used to describe a heterogeneous range of psychological reactions, psychiatric symptoms, and behaviors occurring in people with dementia of any etiology.” The basis of the diagnosis of individual components that make up BPSD revolves around a clinical interview, direct observation of the person with dementia, or a proxy report from a carer or other observer. The three approaches often need to be combined, and some assessment scales rely more on one approach than on another. The key to an accurate diagnosis of BPSD and its effective management lies in a careful assessment of the person with dementia, including carer input.

Much has been learned since the International Psychogeriatric Association's initial consensus conference on behavioral and psychological symptoms of dementia (BPSD) in 1996. In this introduction to the 1999 conference proceedings, I review what we have learned, identify some remaining gaps in the knowledge base, and describe new areas for research and program development.

In traditional medical use, a categorical diagnosis conveys essential (although stereotypic) information about the signs and symptoms of a disease, its treatment, and its prognosis. Its utility derives from its generalizability. However, many of the shortcomings of categorical classification also reflect these same qualities. Diagnoses too often fail to capture important qualities of a disorder or do not sufficiently characterize a patient's particular symptoms. Recent editions of the Diagnostic and Statistical Manual of Mental Disorders (DSM), which have emphasized highly specific entry criteria to establish psychiatric conditions in a more homogeneous fashion, have sometimes resulted in enhanced reliability at the cost of diminished validity. The variability of psychiatric disorders often defies attempts to create strictly defined clusters amenable to syndrome classifications.

“A classification is the reification of an ideological position, of an accepted stand of theory and knowledge. It means creating, defining or confirming boundaries of concepts. These in turn define ourselves, our future and our past…” (Sartorius, 1991). The 10th revision of the International Classification of Diseases (ICD-10), Chapter V on Mental and Behavioral Disorders (World Healthorganization [WHO], 1992, 1993), and the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; American Psychiatric Association, 1994) have been adapted to the current clinical and scientific knowledge of mental disorders. Because ICD-10 has adapted the primarily descriptive and criteria-related approach from DSM-111, the general structures of both classifications are quite similar. However, complete congruency between ICD-10 and DSM-IV has not yet been reached.

Epidemiology, which addresses the health of populations rather than that of individuals, is a complex discipline with a special language and set of methodologies that distinguish it from clinical research. Its objectives include identifying the causes of disease, mapping patterns of use of healthcare services, and measuring the costs to the community of mental and physical illness.

The development of treatment outcome measures has followed a pattern in which treatments are first developed to affect symptoms, and measures are developed concomitantly to detect differences in response rates between the treatment group and a comparison placebo group. For example, in the 1950s, distinct pharmacologic therapies were developed to lower blood pressure and to lessen the hallucinations and delusions associated with schizophrenia. At the same time, measures to assess these latter outcomes were validated.

A variety of behavioral and psychological symptoms are inherent to dementia, such as delusional thinking, hallucinations, agitation, violent behavior, verbal outbursts, wandering, sleep disturbances, and sexually inappropriate behavior (Jackson et al., 1989; Reisberg et al., 1987; Teri et al., 1992; Yeager et al., 1995). Although opinions in the literature differ concerning behavioral problems and how they relate to caregiver burden and institutionalization (Martinson et al., 1995; Mega et al., 1996; Reisberg et al., 1987), this analysis focuses on their role in increasing the level of care once the patient is placed in permanent residential care.

Alzheimer's disease (AD) is the most common cause of dementia, affecting nearly 4 million older Americans (U.S. Department of Health and Human Services, 1996). Behavioral and psychological signs and symptoms of dementia (BPSD), especially agitated behaviors, affect nearly 80% of patients with AD (Jost & Grossberg, 1996). Researchers have speculated that BPSD, especially agitation, are the leading risk factors or triggers for nursing home (NH) admission in AD patients (Chenoweth & Spencer, 1986; Colerick & George, 1986). In this article, we review the literature on risk factors for NH placement in AD, and share preliminary data from an ongoing study at the Saint Louis University /Alzheimer's Association Brain Bank relative to the role of the BPSD as a risk factor for NH placement.

Alzheimer's disease (AD) is associated with a substantial reduction in life expectancy, and mortality has long been evaluated as part of the natural history of this progressive disease. Survival time also plays an important role in projecting the future public health costs of AD. There is now considerable evidence linking mortality in AD with the severity of cognitive impairment and the level of disability in common activities of daily living (Bowen et al., 1996; Jagger et al., 1995; Moritz et al., 1997); established predictors of mortality in AD are listed in Table 1. However, the relationship between mortality and other disease characteristics has received less attention.

There is a direct relationship between years lived beyond age 65 and the number of individuals diagnosed with dementia, primarily Alzheimer's disease (AD). The occurrence of AD has no socioeconomic, geographical, or ethnic limitations. The problem is worldwide. Its magnitude is demonstrated by the following facts: (a) approximately 6% to 8% of persons 65 years or older have AD, and the prevalence of the disease doubles each 5 years after 60 years of age; (b) 30% of 85-year-old individuals can be expected to have the disease; (c) AD affects an estimated 4 million people in the United States, and is expected to affect approximately 14 million Americans within the next few decades; (d) AD patients average 6 to 10 years of comprehensive treatment from symptom onset to death; (e) AD is the fourth leading cause of mortality among elderly Americans, more than 100,000 each year; (f) caregiver attempts at management of the behavioral and psychological symptoms of AD result in up to 50% developing significant psychological distress themselves; and (g) the cost for the management of AD patients is estimated to be between US $80 billion and US $120 billion annually. Primary care is essential for the appropriate diagnosis and treatment of the complex set of behavioral and psychological symptoms of dementia (BPSD) associated with AD.

Dr. Grossberg began the discussion by sharing preliminary data from a study designed to determine risk factors for institutionalization in patients with autopsy-confirmed Alzheimer's disease (AD). Initial findings from this study, which enrolled 100 patients, indicate that the principal predictor of institutionalization is behavioral and psychological symptoms of dementia (BPSD), principally agitation, aggressiveness, and problem wandering. Difficulty with activities of daily living, especially related to continence and hygiene issues, was the second most common predictor of institutionalization. The third most common predictor was lack of a caregiver, either because of death or because of other reasons.

Few studies have examined the relationship between behavioral and psychological symptoms of dementia (BPSD) and neuropathology. Bondareff (1996), who summarized recent work on the subject, concluded that there is no known persecutory, erotomanic, or other specific delusional, illusionary, or hallucinatory center in the brain. Thus, cliniconeuropathologic correlations to BPSD cannot be assumed, because this would require linking complex symptoms to a single, circumscribed alteration of one neuroanatomic area, or one neurotransmitter system, or even one type of histopathologic alteration, regardless of its location. Traditionally, BPSD have been investigated as if they were psychopathologically and neuropsychologically independent of the patient's cognitive disturbances. This may have led to the modest results of some studies. Interestingly, several early studies postulated innovative hypotheses on the neuropathology of BPSD, and sought to verify those hypotheses.

The biologic mechanism by which behavioral and psychological symptoms of dementia (BPSD) occur in some patients with Alzheimer's disease (AD) is not understood, but it may be related to the selected loss of different neuronal populations or specific neurotransmitters. In many patients, these neuronal and neurotransmitter losses are likely to be the end result of the inheritance of a number of genetic risk factors for AD. Thus BPSD may arise indirectly as a result of genetic risk factors for AD. However, an alternative, or possibly complementary, hypothesis is that genetic risk factors for neuropsychiatric phenomena may, in normal circumstances, be clinically silent until neurodegeneration occurs from whatever cause.

The underlying causes of behavioral and psychological symptoms of dementia (BPSD) can be related to biologic factors, such as changes in brain morphology and neurotransmitter functions, and to personal factors, such as previous personality, psychological defenses, and coping strategies. We must also consider the extent to which environmental factors contribute to the etiology of BPSD.

The term behavioral and psychological symptoms of dementia (BPSD) encompasses a diverse cluster of behavioral disturbances, such as restlessness (Hope et al., 1994), aggression (Patel & Hope, 1992), and shouting (Cohen-Mansfield & Werner, 1997), and a variety of psychiatric symptoms, including delusions (Burns et al., 1990), hallucinations (Holroyd & Sheldon-Keller, 1995), depression (Greenwald et al., 1989), and anxiety (Ballard et al., 1996a). Such symptoms are extremely common in patients with dementia and have important associations with burden and depression in caregivers.

Compared with the rather uniform cognitive syndrome in Alzheimer's disease (AD), behavioral and psychological symptoms of dementia (BPSD) are considerably more heterogeneous in terms of incidence, prevalence, and association with disease duration and severity of dementia (Hope et al., 1999). The neurobiologic basis of AD is obviously less of a determinant of noncognitive symptoms than of cognitive symptoms. Therefore, the possible psychological and social causes of BPSD, such as premorbid personality, should be considered. Underlying personality traits not only shape a person's response to normal aging, but also set the stage for a range of responses to age-related stress and brain disease (Agronin, 1998).

Clinical observations leave little doubt that environment has a considerable effect on behavioral and psychological symptoms of dementia (BPSD), and many environmental interventions have been proposed and implemented in an attempt to manage behavioral problems in patients with Alzheimer's disease (AD). However, as Dr. Mintzer commented, there is no theoretical construct for validating environmental interventions. He pointed out the need for consensus on a hypothesis to be tested so that the value of environmental interventions can be proven.

Hallucinations and delusions have been described in all types of dementia, including vascular dementia, Lewy body dementia, and dementia associated with Parkinson's disease. They have been recognized in Alzheimer's disease (AD) since the illness was first described (Alzheimer, 1957).

Current methods for characterizing the behavioral and psychological symptoms of dementia (BPSD) consider the quality of the symptoms together with their frequency, intensity, and, in some instruments, their impact on the caregiver or the environment. Although there have been significant advances in our understanding of these symptoms and their treatment, a key parameter, environmental contingency, has been largely ignored in characterizing symptoms, planning treatments, and evaluating responses. In this brief review, I consider the feasibility and usefulness of subtyping aggressive and agitated symptoms in patients with dementia according to whether these behaviors occur spontaneously or in response to environmental factors.