Chronic psychological distress and risk of Alzheimer's disease in old age.

Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, Ill, USA.
Neuroepidemiology (Impact Factor: 2.48). 02/2006; 27(3):143-53. DOI: 10.1159/000095761
Source: PubMed

ABSTRACT Clinical and pathological data from the Rush Memory and Aging Project were used to test the hypothesis that distress proneness is associated with increased risk of Alzheimer's disease (AD). More than 600 older persons without dementia completed a 6-item measure of neuroticism, a stable indicator of proneness to psychological distress. At annual intervals thereafter, they underwent uniform evaluations that included clinical classification of AD and administration of 18 cognitive tests. Those who died underwent brain autopsy from which composite measures of AD pathology were derived. During a mean of about 3 years of follow-up, 55 people were clinically diagnosed with AD. In analyses that controlled for age, sex, and education, persons with a high level of distress proneness (score = 24, 90th percentile) were 2.7 times more likely to develop AD than those not prone to distress (score = 6, 10th percentile). Adjustment for depressive symptomatology or frequency of cognitive, social, and physical activity did not substantially change this effect. Distress proneness was also associated with more rapid cognitive decline. Among 45 participants who died and underwent brain autopsy, distress proneness was unrelated to diverse measures of AD pathology and was inversely related to cognition after controlling for AD pathology. The results support the hypothesis that distress proneness is associated with increased risk of dementia and suggest that neurobiologic mechanisms other than AD pathology may underlie the association.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Clinical and basic science research suggests that stress and/or changes in central stress signaling intermediates may be involved in Alzheimer's disease (AD) pathogenesis. Although the links between stress and AD remain unsettled, data from our group and others have established that stress exposure in rodents may confer susceptibility to AD pathology by inducing hippocampal tau phosphorylation (tau-P). Work in our lab has shown that stress-induced tau-P requires activation of the type-1 corticotropin-releasing factor receptor (CRFR1). CRF overexpressing (CRF-OE) mice are a model of chronic stress that display cognitive impairment at 9-10 month of age. In this study we used 6-7 month old CRF-OE mice to examine whether sustained exposure to CRF and stress steroids would impact hippocampal tau-P and kinase activity in the presence or absence of the CRFR1-specific antagonist, R121919, given daily for 30 days. CRF-OE mice had significantly elevated tau-P compared to wild type (WT) mice at the AT8 (S202/T204), PHF-1 (S396/404), S262, and S422 sites. Treating CRF-OE mice with R121919 blocked phosphorylation at the AT8 (S202/T204) and PHF-1 (S396/404) sites, but not at the S262 and S422 sites and reduced phosphorylation of c-Jun N Terminal Kinase (JNK). Examination of hippocampal extracts from CRF-OE mice at the ultrastructural level revealed negatively stained round/globular aggregates that were positively labeled by PHF-1. These data suggest critical roles for CRF and CRFR1 in tau-P and aggregation and may have implications for the development of AD cognitive decline.
    Journal of Alzheimer's disease: JAD 08/2014; DOI:10.3233/JAD-141281 · 3.61 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: With the unprecedented number of older adults worldwide, it is important to consider ways of facilitating successful cognitive aging. One way to think of this is by augmenting or bolstering cognitive reserve. Loosely defined, cognitive reserve is considered a neurological reservoir that can be depleted by physiological insults (eg, white matter hyperintensities, oxidative stress) to the brain but yet maintain optimal cognitive functioning. Cognitive reserve is built up or depleted by processes of positive and negative neuroplasticity, respectively. Lifestyle factors such as physical exercise (+), mental stimulation (+), good sleep hygiene (+), substance abuse (-), sedentary lifestyle (-), chronic stress and depression (-), social isolation (-), and poor health (-) can either promote or discourage positive and negative neuroplasticity, which in turn impacts cognitive reserve. Nurses are encouraged to understand these processes so they can help facilitate successful cognitive aging in their patients.
    01/2012; DOI:10.2147/NRR.S32229
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although the initial events of Alzheimer's disease (AD) are still not known, it is clear that the disease in its sporadic form results from the combination of genetic and environmental risk factors. Among the latter, behavioral stress has been increasingly recognized as an important factor in the propagation of AD. However, the mechanisms underlying this modulation remain to be fully investigated. Since stress up-regulates the ALOX5 gene product, 5-lipoxygenase (5LO), herein we investigated its role in modulating stress-dependent development of the AD phenotype. To reach this goal, triple transgenic (3xTg) mice and 3xTg genetically deficient for 5LO where investigated after undergoing a restraint/isolation paradigm. In the present paper we found that 28 days of restraint/isolation stress worsened tau phosphorylation and solubility, increased glycogen synthase kinase 3 beta activity, compromised long-term potentiation, and impaired fear-conditioned memory recall in 3xTg animals, but not in 3xTg animals lacking 5LO (3xTg/5LO-/-). These results highlight the novel functional role that the ALOX5 gene plays in the development of the biochemical, electrophysiological and behavioral sequelae of stress in the AD context. They provide critical support that this gene and its expressed protein are viable therapeutic targets to prevent the onset or delay the progression of AD in individuals exposed to this risk factor.
    Human Molecular Genetics 08/2014; DOI:10.1093/hmg/ddu412 · 6.68 Impact Factor