Models of Behavioral Symptoms
Many attempts have been made to explain the cause of behavioral symptoms of dementia. This seems to me like putting the cart before the horse. If we do not understand the causes or even the process involved in dementia, how can we make an educated guess as to why certain symptoms are manifested?
There are many models of explanation and treatment philosophy for addressing these symptoms. Several are discussed in this section as it is believed the caregiver’s perception of why behaviors occur drives the choice of intervention used to address them.
Need-Driven Dementia-Compromised Behavior (NDB)
The Need-Driven Dementia-Compromised Behavior (NDB) model looks at dementia from the standpoint that the IWD’s behavior expresses a need or goal that he/she is trying to get met or accomplished. Behaviors are influenced by the environment and existing background factors in the following areas:
Neurological – changes in the brain itself (chemical/plaque changes, TIAs, etc.)
Cognitive—memory and attention, use of language
Health status – including emotional state, mobility, and
Psychological – stress level, personality.
Since all these background factors change as the disease progresses, how the needs are expressed also changes (Algase DL et al., 1996). For example, dad would (unfortunately) tell caregivers whom he thought talked too much to shut up early in his dementia. Today, it appears he tunes them out by sleeping/napping rather than using language to address his need for quiet. (Decreased ability for speech is a part of the progression of the disease). It is almost as if you get one behavior figured out, and then another pops up or you receive a response you did not expect. We also noticed a pattern of how he would respond to the changes in caregiving staff on the weekend. Visibly agitated, he became more aggressive—physically and vocally – when someone new would show up to care for him. It seemed he would vigorously protest the change! This is an important reason for consistency of caregiving staff when possible.
The NDB theory closely parallels the person-centered care model. Background factors are changed with the progression of dementia and are not controllable. Modifications of the environment, however, can be made to correspond to individual needs. This model hypothesizes that many behavioral issues result from the individual’s perceived lack of purpose or meaningful activity (Colling and Buettner, 2002). It is important to engage the client in activities to the extent they can participate regardless of the stage of the disease.
Progressively Lowered Stress Threshold Model (PLST)
Progressively Lowered Stress Threshold Model (PLST) postulates that as dementia progresses, the individual’s stress threshold lowers or decreases and provokes behavioral symptoms. These symptoms include sleep disturbances, purposeful wandering or repetitive behavior; aggressive, agitated or anxious behaviors, or noisy behaviors. This model identifies 5 stressors that invoke the behaviors. These stressors include:
Fatigue
Change in the environment, routine, or caregiver
Misleading stimuli or inappropriate stimulus levels (including changes in environment,
routine, caregiver)
Demands that exceed functional ability (including unrealistic expectations to respond),
and
Physical stressors (pain, discomfort, acute illness, depression.) (Volcier and Hurley,
2003).
An earlier summary of this theory (Hall and Buckwalter, 1987) identified a sixth trigger, typically seen at the early stages of dementia. This sixth trigger was identified as perception of loss, defining this as an awareness of lost functioning and activities. It is believed this sixth trigger would be most noticeably present in early stages. The Hall and Buckwalter (1987) study labeled the physical stressors category as delirium, and included trauma, urinary infection, trauma, and adverse drug reactions as causative factors.
The implementation of the PLST model has shown a significant reduction in agitation when frequent exercise occurred throughout the day and naps were limited. It is hypothesized that the stress threshold was reset by activity in this study (Alessi et al. 1999). When caregivers were trained in the use of the PLST method, the caregivers’ mood improved (Buckwalter et al, 1999) and the negative impact of caregiving was decreased (Stolley et al, 2002).
Antecedent-Behavior-Consequence (ABC) Model
The Antecedent-Behavior-Consequence (ABC) Model encourages caregivers to identify the antecedent or trigger for a particular behavior as well as its consequence. This behavioral modification approach involves determining what events precede the behavior and which follow it. Frequency of the behavior is measured, as is the perceived benefit to the person performing it and to the environment. For example, if a client is given a disliked food and throws an eating utensil, the antecedent is the undesired food, the behavior is tossing the utensil, and the consequence is not having to eat the food for a period of time, communication that the food is not wanted or liked, and, depending on the caregiver’s response, discontinuation of the request to eat the food. The antecedents must be carefully observed for repetition over time, however. The antecedent or trigger in this case might have occurred prior to the food being served. An example of an alternate antecedent might be a change in the routine, caregiver, or environment (i.e., sitting with different residents in the dining room, change in the level of noise, or having another need that he/she wants addressed, etc.)
The ABC model is one of patterns. If a particular ABC chain or sequence of behavior is repeated, it is more likely the correct antecedent can be identified and targeted for change. A person-centered, individualized approach—and attentive observation—are essential to this model.
The Habilitation Approach
The Habilitation Approach is a philosophy in dementia care that relies heavily on the existing social skills of the one afflicted with dementia. Sensory cues remain, and behavior cannot be changed directly but the approach of the caregiver and the environment itself can be changed to promote positive responses.
For example, as language decreases, an emphasis on body language, gestures, pictures, and modeling can be used to enhance understanding of communication. Clothing or activities are modified to promote a sense of independence. This philosophy or model addresses 6 domains where positive experiences, emotions, and interactions can be maintained:
-
Physical environment
-
Communication
-
Functional assistance
-
Social
-
Perceptual, and
-
Behavioral. (Raia P, 1999)
One important point of this model is the elimination of reasoning with the IWD. The word ‘no’ is replaced with distraction and the elimination of triggering events (the A in the ABC Model). It is the author’s belief that the habilitation approach should be used in all dementia interactions as it preserves the dignity of patient, the interaction, and the relationship itself.
Psychiatric Model
Instead of the Psychiatric Model, the author would rename this the Pharmaceutical Model as it involves the use of medication to address behavioral symptoms that threaten the safety of the IWD and/or others due to their severity. The psychiatric model does not rely on a specific diagnosis, however. This model recommends that a physician prescribe medication that is relevant to the manifested behaviors. For example, a withdrawn, irritable, despondent, negative set of behaviors would be considered symptoms of depression and an antidepressant might be prescribed. The standard geriatric “start low and go slow” advice for prescribing and titrating would apply (Tariot, 1999).
Comprehensive Model
The Comprehensive Model incorporates behavioral and psychiatric approaches to the management of behavioral symptoms of dementia, realizing that the personality of the client remains intact until the later stages of dementia and may become more pronounced as it progresses (Chatterjee A. et al, 1992).
Volicer and Hurley (date) describe a chart of levels describing the interaction of levels within this model. As mentioned previously, the dementia and the individual’s personality, which remains intact for most of the dementia journey, interact constantly and help to drive the explanations of the behavior. First, an inner circle shows the primary consequences of dementia: functional impairment, delusions and hallucinations, and mood disorders. These issues result in the behaviors in the second ring of the model and correspond to the areas affected by the dementia. For example, functional impairment results in a need for assistance in ADLs, as well as an inability to initiate meaningful activities (hobbies, meal prep, etc.) This, in turn, can result in the IWD’s response to additional caregiving requirements with resistance to care, refusal to eat, and perhaps combativeness. The management of these behaviors is through consistency of routine in caregiving, providing meaningful activities at the appropriate cognitive level, adaptive clothing, or fewer choices of apparel, tailoring meals to taste and consistency preferences, etc.
Issues with insomnia and interference with other resident points to changes needed in the social environment. A reduction in noise or activity in the room, scheduled exercise during the day, increased activity and decreased napping can result in more positive and desired behavioral responses.
The Comprehensive Model states that often the symptoms are treated without regard to the underlying causes of the behavior. An example of this would be a client presenting with insomnia and prescribed a medication for sleep. The underlying cause, lack of activity during the day, noise disruption, hunger at night, etc. should be examined and addressed prior to the use of medication, which, in turn, can add additional variables to the mix.
An example of this follows. Although my father’s dementia influences his care in many ways, he also has stress fractures and bone-on-bone in his back causing chronic pain. The treatment prescribed by the hospice agency tries to address the back pain itself without consideration of the fact that individuals with Vascular Dementia (VaD) may be more susceptible to medications as well as suffer from chronic pain unrelated to an injury. The literature suggests individuals with VaD have centralized sensitivity, or the brain’s insistence that the nerve cells registering pain continue firing even without the presence of a specific pain site. The hospice doctors continue to prescribe antidepressants without addressing the foundation of the depressive mood: pain. It is an endless cycle of medications that are administered for symptoms without consideration of the CAUSE of the issue itself.
The authors also discuss depression, “Depression was significantly more common among residents with dementia who manifested physical or verbal aggression than in those without such behaviors” (Menon, et al, 2001.) Depression may also aggravate resistiveness to care: many depressed individuals without dementia also ignore ADL. According to Menon et al (2001), depression, hallucinations, and delusions often respond well to low-dose medications.
Sources:
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Algase DL, Beck C, Kolanowski A, et al. Need-driven dementia-compromised behavior: an alternative view of disruptive behavior. Am J Alzheim Dis. 1996;11:10-19.
Buckwalter KC, Gerdner L, Kohout F, et al. A nursing intervention to decrease depression in family caregivers of persons with dementia. Arch Psych Nurs. 1999;13:80-88.
Chatterjee A, Strauss ME, Smyth KA, Whitehouse PJ. Personality changes in Alzheimer’s disease. Arch Neurol. 1992;49:486-491.
Colling KB, Buettner LL. Simple pleasures: interventions from the Need-Driven Dementia-Compromised Behavior model. J Gerontol Nurs. 2002;28:16-20.
Hall G, Buckwalter K. A conceptual model for planning and evaluating care of the client with Alzheimer’s disease. Arch Psychiatr Nurs, 1987;1:399-406.
Menon AS, Gruber-Baldini AL, Hebel JR, et. Al. Relationship between aggressive behaviors and depression among nursing home residents with dementia. Int J Ger Psychiatr. 2001;16:139-146.
Raia P. Habilitation therapy: a new starscape. In: Volicer L, Bloom-Charette L, eds. Enhancing the Quality of Life in Advanced Dementia. Philadelphia: Taylor & Francis; 1999:21-37.
Stolley JM, Reed D, Buckwalter KC. Caregiving appraisal and interventions based on the progressively lowered stress threshold model. Am J Alzheim Dis. 2002;17:110-120.
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