Chronic stress is associated with high cortisol levels and emotional coping mechanisms in amnestic mild cognitive impairment

[Les effets de la méditation de pleine conscience sur les symptômes cognitivo- émotionnels dans le trouble cognitif léger et la maladie d'Alzheimer : une revue de littérature narrative]

La maladie d'Alzheimer se manifeste par des troubles de la mémoire et un déclin cognitif plus général, le plus souvent associés à des troubles de l'humeur et du comportement. Les traitements médicamenteux ayant une efficacité assez modeste, il apparaît nécessaire de leur associer une prise en charge non pharmacologique. La méditation de pleine conscience, qui a des effets bénéfiques sur le fonctionnement cognitif et sur l'état émotionnel, semble être une piste intéressante. Cette revue de littérature narrative se propose de recenser les études ayant testé l'efficacité d'une intervention basée sur la pleine conscience auprès de personnes souffrant de la maladie d'Alzheimer ou à risque de développer cette maladie. Il apparaît que ces interventions présentent un intérêt pour réduire les symptômes cognitifs (troubles attentionnels et mnésiques notamment) et émotionnels (affects dépressifs et anxiété en particulier). Cependant, elles nécessitent un certain nombre de modifications pour être adaptées à ce public.

Common Neuropsychiatric S ymptoms in Alzheimer's Disease, Mild Cognitive Impairment, and Subjective Memory Complaints: A Unified Framework

The Alzheimer's disease (AD) continuum is a unique spectrum of cognitive impairment that typically involves the stages of subjective memory complaints (SMC), mild cognitive impairment (MCI), and AD dementia. Neuropsychiatric symptoms (NPS), such as apathy, anxiety, stress, and depression, are highly common throughout the AD continuum. However, there is a dearth of research on how these NPS vary across the AD continuum, especially SMC. There is also disagreement on the effects of specific NPS on each stage of the AD continuum due to their collinearity with other NPS, cognitive decline, and environmental factors (e.g., stress). In this article, we conduct a novel perspective review of the scientific literature to understand the presence of NPS across the AD continuum. Specifically, we review the effects of apathy, depression, anxiety, and stress in AD, MCI, and SMC. We then build on this knowledge by proposing two theories of NPS' occurrence across the AD continuum. Consequently, we highlight the current landscape, limitations (e.g., differing operationalization), and contentions surrounding the NPS literature. We also outline theories that could clear up contention and inspire future NPS research.

Psychological and Neurophysiological Effects of Robot Assisted Activity in Elderly People With Cognitive Decline

Robot-assisted activity (RAA) is a non-pharmacological therapy used to treat behavioral and psychological symptoms of dementia. This study investigated the immediate effects of RAA on psychological and neurophysiological indices. Twenty-eight elderly people were assigned to the cognitive decline group (n = 11) or control group (n = 17) based on their Mini-Mental State Examination scores. After 5-min RAA sessions that involved patients interacting with a communication robot, patient emotions and mood states were measured, and resting-state EEG activity and salivary cortisol were assessed before and after RAA. We found that compared with those in the control group, participants in the cognitive decline group did not enjoy RAA using the communication robot. This was corroborated by EEG findings indicating decreased relaxation immediately after RAA exposure. These results suggested that participants with cognitive decline had difficulty understanding the contents of communication with the robot. Our results indicated that elderly people who have cognitive decline and use day-service centers are less likely to experience the immediate benefits of RAA, including positive emotions and mental relaxation. To conduct effective RAA for such populations, it may be useful to select a method that is better understood and enjoyed by participants.

Minimally-invasive methods for examining biological changes in response to chronic stress: A scoping review

BACKGROUND

Nurse researchers are increasingly interested in incorporating biological indicators related to chronic stress, or repeated or constant exposure to psychological stressors. Minimally invasive collection methods may improve access to vulnerable populations.

OBJECTIVE

To map biological indicators measured through minimally invasive methods investigating biological changes in response to chronic stress.

DESIGN, DATA SOURCES, AND METHODS

The paper seeks to answer two questions: What are the characteristics of the minimally-invasive methods used to measure the biological correlates of chronic stress? What are the limitations regarding the use of the minimally-invasive methods and/or biological indicators identified above? Authors completed a scoping review following guidelines from the Joanna Briggs Institute Manual and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for Scoping Reviews. A literature search was completed in PubMed, PsycINFO, and Scopus. 2518 articles were screened and 145 studies were included. Data were extracted using a standardized extraction tool, compiled, and coded.

RESULTS

Studies included minimally-invasive methods to measure the hypothalamic-adrenal-pituitary axis (N = 173), immune and inflammatory markers (N = 118), and adult neurogenesis (N = 6). Cortisol was most frequently measured (N = 136), usually in saliva (N = 86). Studies included a variety of limitations for the methods and indicators, including concerns about timing and accuracy of collection, frequency of sampling, and controlling for acute stressors.

CONCLUSIONS

Nurse researchers have access to many minimally-invasive methods to measure altered biological processes related to chronic stress. A gap identified by this review is the paucity of minimally-invasive methods for investigating neurogenesis; the measurement of brain derived neurotrophic factor in plasma is a distal proxy and further research is needed to test the response of peripheral levels to psychosocial stress interventions. Additionally, while this scoping review allows nurse researchers to consider possible biological indicators to include in their research, future research is still needed on some of the basic premises of stress research, including agreement on the conceptualization of chronic stress.

Stress-Induced Neurodegeneration: The Potential for Coping as Neuroprotective Therapy

Stress responses are essential for survival, but become detrimental to health and cognition with chronic activation. Chronic hypothalamic-pituitary-adrenal axis release of glucocorticoids induces hypothalamic-pituitary-adrenal axis dysfunction and neuronal loss, decreases learning and memory, and modifies glucocorticoid receptor/mineralocorticoid receptor expression. Elderly who report increased stress are nearly 3 times more likely to develop Alzheimer's disease, have decreased global cognition and faster cognitive decline than those reporting no stress. Patients with mild cognitive impairment are more sensitive to stress compared to healthy elderly and those with Alzheimer's disease. Stress may also transduce neurodegeneration via the gut microbiome. Coping styles determine hippocampal mineralocorticoid receptor expression in mice, indicating that coping modifies cortisol's effect on the brain. Identifying neuroprotective coping strategies that lessen the burden of stress may prevent or slow cognitive decline. Treatments and education designed to reduce stress should be recognized as neuroprotective.

Mindfulness and psychoeducation to manage stress in amnestic mild cognitive impairment: A pilot study

Objectives: Amnestic mild cognitive impairment (aMCI) often corresponds to the prodromal stage of Alzheimer disease (AD). The aMCI stage represents a crucial time window to apply preventive interventions in an attempt to delay cognitive decline. Stress, one of AD's modifiable risk factors frequently co-occurring with aMCI, stands out as a key intervention target. The goal of this study was to assess the impacts of two non-pharmacological interventions, mindfulness and psychoeducation, on stress at the psychological and physiological levels among aMCI older adults. Methods: Forty-eight aMCI participants were randomized between a mindfulness-based intervention (MBI) and a psychoeducation-based intervention (PBI) for eight weekly sessions. Anxiety symptoms, perceived stress levels, cortisol awakening response (CAR), and coping strategies were assessed pre- and post-intervention. Mindfulness attitudes and time dedicated to at-home meditative practices were evaluated in the MBI group. Results: The main results revealed a slight reduction of the CAR among MBI participants who practiced meditation at home the most and a decrease in perceived stress levels in the PBI group. Both interventions enhanced problem-focused coping strategies. Conclusion: In sum, this pilot study supports the potential of MBI and PBI to reduce stress at the physiological and psychological level, respectively, and increase coping strategies in older adults at risk for AD.

Morning cortisol levels in schizophrenia and bipolar disorder: a meta-analysis

Increased peripheral levels of morning cortisol have been reported in people with schizophrenia (SZ) and bipolar disorder (BD), but findings are inconsistent and few studies have conducted direct comparisons of these disorders. We undertook a meta-analysis of studies examining single measures of morning cortisol (before 10 a.m.) levels in SZ or BD, compared to controls, and to each other; we also sought to examine likely moderators of any observed effects by clinical and demographic variables. Included studies were obtained via systematic searches conducted using Medline, BIOSIS Previews and Embase databases, as well as hand searching. The decision to include or exclude studies, data extraction and quality assessment was completed in duplicate by LG, SM and AS. The initial search revealed 1459 records. Subsequently, 914 were excluded on reading the abstract because they did not meet one or more of the inclusion criteria; of the remaining 545 studies screened in full, included studies were 44 comparing SZ with controls, 19 comparing BD with controls, and 7 studies directly comparing schizophrenia with bipolar disorder. Meta-analysis of SZ (N=2613, g=0.387, p=0.001) and BD (N=704, g=0.269, p=0.004) revealed moderate quality evidence of increased morning cortisol levels in each group compared to controls, but no difference between the two disorders (N=392, g=0.038, p=0.738). Subgroup analyses revealed greater effect sizes for schizophrenia samples with an established diagnosis (as opposed to 'first-episode'), those that were free of medication, and those sampled in an inpatient setting (perhaps reflecting an acute illness phase). In BD, greater morning cortisol levels were found in outpatient and non-manic participants (as opposed to those in a manic state), relative to controls. Neither age nor sex affected cortisol levels in any group. However, earlier greater increases in SZ morning cortisol were evident in samples taken before 8 a.m. (relative to those taken after 8 a.m.). Multiple meta-regression showed that medication status was significantly associated with morning cortisol levels in SZ, when the effects of assay method, sampling time and illness stage were held constant. Heightened levels of morning cortisol in SZ and BD suggest long-term pathology of the hypothalamic-pituitary-adrenal (HPA) axis that may reflect a shared process of illness development in line with current stress-vulnerability models.

Queixa subjetiva de comprometimento da memória em idosos saudáveis: influência de sintomas depressivos, percepção de estresse e autoestima

O presente estudo analisou a relação entre percepção de estresse, sintomas depressivos e autoestima em idosos com e sem queixa subjetiva de comprometimento de memória. Foram incluídos 204 idosos (104 sem e 100 com queixa de memória) avaliados a partir do instrumento Memory Assessment Complain Questionnaire (MAC-Q). O protocolo de estudo incluiu a Escala de Estresse Percebido (EEP), a Escala de Depressão Geriátrica (GDS) e a Escala de Autoestima de Rosenberg (EAE). Os idosos com queixa de comprometimento apresentaram escores significativamente maiores na EEP e GDS e menores na EAE (p < 0.001). Foi observada correlação negativa entre o escore do MAC-Q e EPP (p < 0.001) e EAE (p = 0.01). A análise de regressão multivariada identificou somente o estresse como fator preditor da queixa subjetiva de memória. Esses dados sugerem que a percepção de estresse e os sintomas depressivos estão associados com a queixa de memória em idosos.