Research roundup: Understanding Alzheimer’s disease

This issue focuses on recent research related to predispositions and interventions for Alzheimer’s disease.

Classified as a neurodegenerative disorder, Alzheimer’s disease (AD) remains the sixth leading cause of death in the United States. At times, symptoms of AD may be discounted as manifestations of stress or age-related concerns, whereas they primarily reflect cognitive deficiencies. These deficits relate to difficulties in memory, maintenance of mood and behavior and overall autonomy. 

In addition, AD is characterized by individual differences, which complicates efforts to develop appropriate interventions for those who suffer from AD. 

Current regimens primarily involve pharmaceutical, psychosocial and behavioral interventions that attempt to slow the progression of AD. Methods to stop and/or reverse the progression of this disease currently do not exist. 

In addition to reviewing the following research summaries, psychologists are encouraged to explore the literature more completely to determine what may be useful to them in practice. 

Anstey, K.J., Cherbuin, N., & Herath, P.M. (2013). Development of a new method for assessing global risk of Alzheimer’s disease for use in population health approaches to prevention. Prevention Science, 14, 411-421. doi: 10.1007/s11121-012-0313-2

Summary 

The authors of this study conducted an extensive systematic review/meta-analysis in order to derive possible risk and protective factors associated with Alzheimer’s disease (AD). The study focused primarily on AD risk, as opposed to diagnosis. The authors developed a novel methodology to create a self-report risk index for AD resulting in the Australian National University Alzheimer’s Disease Risk Index (ANU-ADRI). 

Through four iterative stages, the study yielded 10 risk factors and five protective factors. An algorithm was then developed in order to derive odds ratios for each risk factor (age, sex, body mass index, diabetes, depression, serum cholesterol, traumatic brain injury, smoking, alcohol intake and pesticide exposure) and each protective factor (education, social engagement, physical activity, cognitive activity and fish intake). The methodology used not only allowed for greater assessment of such factors, but overall targeted risk reduction as well. 

Practical Implications 

While research may be at the beginning stages of uncovering relationships between risk and protective factors and development of AD, this study points to how certain robust risk and protective factors generally interact with AD. Future studies may focus on actually manipulating these factors. Manipulation could potentially facilitate greater understanding of the more specific interactions between these factors and AD, and could thus lead to more effective means of reducing prevalence. In the meantime, when psychologists work with individuals with a family history of AD or concerns about developing AD, psychologists can review potential risk and protective factors with individuals to more realistically appraise concerns and determine whether possible behavior changes to increase health might be beneficial. 

Crowe, J., Gabriel, L. (2013). Errorless learning and spaced retrieval training for clients with Alzheimer’s dementia. School of Pharmacy and Allied Health Professions, 31(3), 254-267. doi:10.3109/02703181.2013.796037 

Summary 

The authors of this study conducted an extensive review of the literature to examine different types of memory systems in humans, and how they can be better understood, in order to assist those who suffer from AD with activities of daily living (ADL). 

Three separate actions are involved in memory and learning: encoding, storing and retrieving. These actions are able to operate at a conscious level (implicit), or at an unconscious level (explicit). For people with AD, actions that are explicit more often succumb to the neurodegenerative processes, as opposed to actions that are implicit. Therefore, psychosocial intervention efforts often target implicit processing of information as that is generally more efficient in clients with AD. 

Currently, two main learning strategies are used to enhance implicit memory in a person with AD: errorless learning and spaced retrieval training. The first focuses on the reduction or prevention of errors made during a learning process, while the latter focuses on information that is recalled progressively over long periods of time. 

Errorless learning operates on an information storage level. There are two possible techniques related to errorless learning: The first technique involves providing the answer to a question and/or sequence to the person with AD and having the person repeat the question and/or perform the sequence. The second technique involves dividing tasks into smaller, sequential steps and modeling the tasks before having the person with AD complete them. At the same time, the clinician discourages guessing, corrects errors and fades the cues or prompts. 

Spaced retrieval training also elicits correct responses based oncertain physical or verbal cues, and the allotted time between each cue is gradually increased. Both types of psychosocial intervention methods have been shown to be effective tools at facilitating new learning. Moreover, both methods provide step-by-step guidance, which can allow people with AD to learn and store information at an increased capacity although they will continue to experience cognitive difficulties. 

Practical Implications 

Errorless learning and spaced retrieval are behavioral strategies that can help the brain become more adept at encoding, storing and retrieving memory. Psychologists trained in these strategies may employ them routinely in their work with people with AD; others may wish to learn more to determine if these mechanisms can be adapted to treatment in order to better help individuals with AD get the most from their psychological treatment. Psychologists working with family caregivers of someone with AD may want to identify referrals or resources so family members are aware of how to access this expertise. 

McClendon, M.J. & Smyth, K.A. (2013). Quality of informal care for persons with dementia: dimensions and correlates. Aging & Mental Health, 17(8), 1003 – 1015. doi: 10.1080/13607863.2013.805400

Summary

McClendon and Smyth collected self-report data from 148 informal caregivers of those with AD and used factor analysis and structural equation modeling to uncover elements of both high and low quality of care. The authors sought out dimensions of quality of care, as well as caregiver personality traits and coping strategies linked to better and worse quality of care. Person-centered care has been shown to be indicative of high quality care, which promotes the facilitation of autonomy and respect for care recipients, and thus was the element of particular interest. 

To measure qualities of caregiving, the authors used a 14-item Exemplary Care scale containing various questions regarding care giving (CG) words, actions and feelings. To measure caregiver personality traits, authors used the 44-item Big Five Inventory, which focuses on the five-factor model of personality. Additionally, coping strategies were noted with the five-point Pruchno and Resch (1989) scale, which includes questions relating to 16 different tasks and situations that are likely to occur during typical informal caregiving. 

Factors associated with higher quality caregiving included personalized, respectful and compensatory care. These specific factors promote care recipient self-expression and trust. In contrast, factors associated with poorer quality caregiving were found to be punitive, controlling and withdrawing actions; such factors reflected anger and disdain. Personality traits related to quality of care found that openness, conscientiousness and neuroticism characterized higher quality of care, while extraversion predominately characterized poorer quality of care. Furthermore, the avoidance/escape strategy of wishful coping was found to have the strongest link to poorer quality of care.

Practical Implications

Psychologists frequently provide support and education to caregivers. This study suggests specific arenas to attend to in order to promote high quality care. For instance, helping caregivers focus on person-centered care and developing caregivers’ capacity to promote realistic autonomy and respect in care recipients could be a focus of psychological interventions. Additionally, developing caregivers’ coping strategies will likely help them provide more effective care to their family members. While excellent programs for caregivers do exist, not all communities may have such support or family caregivers choose not to participate so individual psychologists can utilize some of these strategies with family members as appropriate.