Does older adults' cognition particularly suffer from stress? A systematic review of acute stress effects on cognition in older age

Is age more than a number? Accounting for adult development and aging in the study of psychoneuroimmunology, stress, and health

Traditional stress-and-health models link stressors to their health consequences through a well-characterized cascade. Most of the research assumes that the stress-health sequence unfolds in the same way across adulthood, whether a person is 25 years old or 80. Taking a "developmental" or "lifespan" approach has been synonymous with studying the lasting health impacts of early life experiences. However, theories and evidence from adult development and geroscience suggest that stress-health dynamics evolve in important ways over the adult lifespan-from the stressors that we encounter, to the emotion regulation strategies that we use to confront challenges, to the psychosocial resources at our disposal, to the cellular milieu, and thus to the magnitude of stressors' biological and functional consequences. This critical review synthesizes theoretical perspectives and selected empirical literature on the social-emotional and biological dimensions of aging to promote an Integrative Model of Aging, Stress, and Health. Through this integration, the model illustrates how an interdisciplinary, developmental perspective can enrich our understanding of stress's consequences for health across adulthood. It also seeks to guide a new generation of research questions that confront aging with a multidimensional approach. The piece concludes with personal reflections on the foundational legacy of the author's mentor, Dr. Janice Kiecolt-Glaser.

Influence of stress-specific interventions on biomarker levels and cognitive function in cancer patients: Systematic review and meta-analysis

PURPOSE

Cancer patients' psycho-physiological health is seriously affected by long-term exposure to stress. Many studies have explored the impact of stress-specific interventions on cancer patients' biomarker levels and cognitive functions. However, the current research findings are inconsistent, and their statistical power is limited by the small samples. Therefore, we conducted this meta-analysis to verify the effect of stress-specific interventions on cancer patients.

METHODS

The literature involved nine databases from the inception until January 13, 2024, extracted 19 randomized controlled trials (RCTs). Review Manager (RevMan) 5.4 software was used to perform a meta-analysis, and the revised Cochrane risk of bias tool (RoB2) was utilized for quality evaluation.

RESULTS

Nine RCTs were assessed as having a low risk of bias, and others had a moderate risk. The results showed that stress-specific interventions had beneficial effects on patients' subjective cognition but uncertain impacts on their executive function, tumour necrosis factor-α level, morning cortisol level, and no effect on cortisol at other times, interleukin (IL)-10, IL-8, IL-6, IL-1, and C-reactive protein.

CONCLUSION

More rigorous studies are required to elucidate the influence of stress-specific interventions on biomarker levels. The potential mechanism by which stress-specific interventions affect the cancer patient's cognitive function remains unclear.

Longitudinal associations of effort and reward at work with changes in cognitive function: evidence from a national study of U.S. workers

PURPOSE

This study aimed to examine longitudinal associations of workplace effort and reward with changes in cognitive function among United States workers.

METHODS

Data from the national, population-based Midlife in the United States (MIDUS) study with a 9-year follow-up were used. Validated workplace effort and reward scales were measured at baseline, and cognitive outcomes (including composite cognition, episodic memory, and executive functioning) were measured with the Brief Test of Adult Cognition by Telephone (BTACT) at baseline and follow-up. Multivariable linear regression analyses based on generalized estimating equations (GEE) examined the longitudinal associations under study.

RESULTS

Among this worker sample of 1,399, after accounting for demographics, socioeconomics, lifestyle behaviors, health conditions, and job control, high reward at baseline was associated with increased composite cognition (regression coefficient: 0.118 [95% CI: 0.049, 0.187]), episodic memory (0.106 [0.024, 0.188]), and executive functioning (0.123 [0.055, 0.191]) during follow-up. The joint exposure of 'high effort and high reward' was also associated with increased composite cognition (0.130 [0.030, 0.231]), episodic memory (0.131 [0.012, 0.250]), and executive functioning (0.117 [0.017, 0.216]), while the combination of 'low effort and high reward' was associated with increased composite cognition (0.106 [0.009, 0.204]) and executive functioning (0.139 [0.042, 0.235]).

CONCLUSION

Findings suggest that workplace high reward is related to improved cognitive scores among United States workers. Future research should investigate larger cohorts over longer timespans and expand into disease outcomes such as dementia. If these findings emerge as causal, relevant workplace rewards to promote worker cognitive health should be considered.

Age differences in acute stress and PTSD symptoms during the 2023 Israel-Hamas war: Preliminary findings

Traumatic exposure can result in acute stress symptoms in the immediate aftermath and post-traumatic stress disorder (PTSD) symptoms that persist beyond the initial weeks. Both short-term and long-term reactions require research and clinical attention. There is considerable evidence for age differences in PTSD, and older adults frequently present lower rates of PTSD compared to young adults. Much less is known concerning age differences in acute reaction or the extent to which age differences in PTSD are affected by age differences in acute stress. The current study examined acute stress and PTSD symptoms among young and older adult Israelis during the 2023 Israel-Hamas war. A web-based sample of 428 participants (mean age = 48.36 ± 16.29) completed retrospective accounts of pre-war psychological distress and acute stress in the first week of the war and further reported current PTSD symptoms. Rates of elevated levels of acute stress symptoms and probable PTSD were significantly higher among young adults (24.8% and 42.8%, respectively) compared to their older counterparts (3.7% and 13.7%, respectively). Age differences in probable PTSD remained significant even after controlling for other demographics, traumatic exposure, pre-war psychological distress, and acute stress symptoms. These preliminary findings further attest to the impressive resilience manifested by older adults during wartime. Moreover, as age differences in probable PTSD were not fully explained by acute reactions, unique mechanisms may be mobilized by older adults to cope with warfare trauma in the short- and long term.

Acute stress impacts reaction times in older but not in young adults in a flanker task

Acute psychosocial stress effects on inhibition have been investigated in young adults, but little is known about these effects in older adults. The present study investigated effects of the Trier Social Stress Test on cognitive inhibition (i.e., ability to ignore distracting information) using a cross-over (stress vs. control) design in healthy young (N = 50; 18-30 years; Mage = 23.06) versus older adults (N = 50; 65-84 years; Mage = 71.12). Cognitive inhibition was measured by a letter flanker task and psychophysiological measures (cortisol, heart rate, subjective stress) validated the stress induction. The results showed that while stress impaired overall accuracy across age groups and sessions, stress (vs. control) made older adults' faster in session 1 and slower in session 2. Given that session 2 effects were likely confounded by practice effects, these results suggest that acute psychosocial stress improved older adults' RTs on a novel flanker task but impaired RTs on a practiced flanker task. That is, the interaction between stress and learning effects might negatively affect response execution when testing older adults on flanker tasks. If confirmed by future research, these results might have important implications especially in settings where repeated cognitive testing is performed under acute stress.

Adult age differences in the psychophysiological response to acute stress

Age-related differences in the psychophysiology of the acute stress response are poorly understood given the limited number of studies and the high heterogeneity of findings. The present study contributes by investigating age differences in both the psychological and physiological responses to acute stress in a sample of healthy younger (N = 50; 18-30; M_age = 23.06; SD = 2.90) and older adults (N = 50; 65-84; M_age = 71.12; SD = 5.02). Specifically, the effects of psychosocial stress (i.e., age-adapted Trier Social Stress Test) were investigated at numerous timepoints throughout the stress response phases (i.e., baseline, anticipation, reactivity, recovery) on cortisol, heart rate, subjective stress, and anticipatory appraisal of the stressful situation. The study was conducted in a between-subject (younger vs. older) cross-over (stress vs. control) design. Results revealed age-related differences in both physiological and psychological variables: older adults had overall lower salivary cortisol levels in the stress and control conditions and lower stress-induced cortisol increase (i.e., AUCi). In addition, older adults' cortisol reactivity was delayed compared to younger adults. Older adults showed a lower heart rate response in the stress condition while no age differences were observed in the control condition. Finally, older adults reported less subjective stress and a less negative stress appraisal during the anticipation phase than younger adults, which could potentially explain lower physiological reactivity in this age group. Results are discussed in relation to the existing literature, potential underlying mechanisms, and future directions for the field.

Understanding the relationships between physiological and psychosocial stress, cortisol and cognition

Stress is viewed as a state of real or perceived threat to homeostasis, the management of which involves the endocrine, nervous, and immune systems. These systems work independently and interactively as part of the stress response. The scientific stress literature, which spans both animal and human studies, contains heterogeneous findings about the effects of stress on the brain and the body. This review seeks to summarise and integrate literature on the relationships between these systems, examining particularly the roles of physiological and psychosocial stress, the stress hormone cortisol, as controlled by the hypothalamic-pituitary-adrenal (HPA) axis, and the effects of stress on cognitive functioning. Health conditions related to impaired HPA axis functioning and their associated neuropsychiatric symptoms will also be considered. Lastly, this review will provide suggestions of clinical applicability for endocrinologists who are uniquely placed to measure outcomes related to endocrine, nervous and immune system functioning and identify areas of intervention.