Jee Eun Kang

Loneliness is linked to a wide range of negative outcomes, including worse emotional well-being. Although prior research has demonstrated the relationship between loneliness and typical levels of negative and positive emotions, the degree to which loneliness is associated with emotional instability, a potential indicator of unhealthy patterns of emotional experiences, is unknown. We evaluated whether individual differences in loneliness were related to instability across days in positive emotions (PE) and negative emotions (NE) in daily life. A diverse community sample of 252 adults (age 25-65) completed a baseline assessment of loneliness followed by 14 days of ecological momentary assessments, during which participants reported PE and NE five times each day. Loneliness was significantly associated with greater instability in both PE and NE, after adjusting for demographic characteristics, objective social isolation, and person-mean emotion levels. Notably, the association with PE instability remained significant even after controlling for depressive symptoms, whereas the association with NE instability was attenuated and no longer significant. These findings suggest that loneliness is characterised not only by differences in average emotional states but also by greater emotional variability, particularly in PE, which may be a key feature linking loneliness to broader health and well-being outcomes.

Loneliness is a worldwide concern with significant health implications that may be a significant risk factor for Alzheimer’s disease and related dementias. In light of the importance of detecting early cognitive changes and risk factors influencing cognitive health, this study examined whether chronic loneliness predicted cognitive changes among young and middle-aged adults. This study utilizes data from a longitudinal measurement burst study spanning over two years, comprising three waves of data collection. A systematically recruited young to mid-life adult sample (25- 65 years) included 172 racially and economically diverse participants who provided information about loneliness for at least two consecutive waves. Chronic loneliness was defined based on the validated multi-item PROMIS Social Isolation scale. We assessed working memory, processing speed, and spatial memory in a measurement burst design using mobile cognitive assessments. Multilevel growth models were conducted to examine whether chronic loneliness was associated with changes in cognitive performance during the study period of up to two years. Results revealed that chronic loneliness was not associated with baseline performance of working memory, processing speed, spatial memory or global cognitive performance, but chronic loneliness was associated with differential cognitive trajectories, specifically a lack of retest related improvement. There were no significant changes in cognitive performance for the chronic loneliness group across waves, whereas significant improvements were observed in those who were not chronically lonely. This study offers insights into the impact of chronic loneliness on cognitive changes in young and middle-aged adults, revealing that chronically lonely individuals did not exhibit the practice-related improvements that are commonly observed in longitudinal studies. Findings suggest the potential significance of identifying and addressing chronic loneliness promptly to prevent potential cognitive consequences of chronic loneliness.

Background: Loneliness is linked with risk for cognitive decline and dementia among older adults, but the degree to which it predicts future risk is unclear. To investigate if loneliness acts as a predictor of cognitive decline, this study employed a measurement burst design using data from the Einstein Aging Study, where loneliness and cognition were repeatedly assessed daily, for several days, across several years. In this type of data, a major challenge to detecting subtle cognitive changes is the presence of retest/practice effects. We employed a novel process modeling approach (Bayesian Double Exponential Model; BDEM) to distinguish retest learning effects from genuine longitudinal cognitive changes.Method: Participants (n = 313; English‐speaking, community‐residing adults aged ≥70) underwent up to six waves of annual assessments. Each wave included a 16‐day ambulatory ecological momentary assessment (EMA) burst on mobile phones. Ambulatory assessments consisted of self‐report (including a question about feeling lonely now) and cognitive tests, conducted multiple times daily. This study analyzed the spatial working memory task.Cognitive parameters capturing retest learning rate, peak performance (disentangled from retest learning) and long‐term changes in peak performance were estimated simultaneously using the BDEM. Regression analyses examined associations between mean and standard deviation (SD) of EMA loneliness at baseline and cognitive markers, controlling for demographics and mild cognitive impairment (MCI) status at baseline.Result: A higher mean and a higher variability (SD) of EMA loneliness at baseline predicted higher baseline asymptotic (peak) performance, suggesting worse peak cognitive performance at baseline. However, neither mean level nor variability of EMA loneliness at baseline predicted changes in peak performance after baseline. Notably, a higher variability of EMA loneliness was also associated with slower learning rates from repeated testing across bursts.Conclusion: This study reveals that the level and variability of loneliness in daily life, measured in near‐real time, predict concurrent peak performance and long‐term learning rates in working memory among older adults. Results, particularly regarding loneliness variability, suggest that the experience of loneliness has implications for long‐term learning rates. Not only the mean level of loneliness, but also variations in loneliness, have separate predictive value for cognitive performance over time.

Objectives: Despite extensive efforts to study individual differences in loneliness and neurocognitive health, little is known about how within-person changes in state loneliness relate to cognitive performance. This study addressed this gap by examining the association between within-person variation in state loneliness and cognitive performance assessed objectively in daily life. Methods: Participants were 313 community-dwelling older adults (70–90 years) who reported momentary feelings of loneliness and completed smartphone-based cognitive tests 5 times daily for 14 consecutive days. Mobile cognitive tests assess visual associative memory, processing speed, and spatial memory. Results: At the day level, average state loneliness levels were negatively related to cognitive performance on the same day and subsequent day. Consistent with the day-level analysis, momentary assessments of increased loneliness were consistently linked to worse cognitive performance on concurrent assessments. However, moments characterized by lower cognitive performance predicted higher levels of loneliness 3–4 hr later (next occasion), but not vice versa. Discussion: The findings suggest a prospective association between loneliness and cognitive performance, with higher daily loneliness negatively associated with cognitive performance on the same day and predicting worse performance the following day. Notably, within a single day, lower cognitive performance at a given moment predicted elevated loneliness later in the day. This highlights a complex, reciprocal relationship—loneliness predicting and being predicted by cognitive performance depending on timescale.

Loneliness influences how people experience and respond to stressors, which may account for its role as a risk factor for morbidity and mortality. The present study was motivated by emerging evidence that affective responses to minor daily events have long‐term implications for health and well‐being. Specifically, we evaluated how individual differences in loneliness relate to the frequency of everyday stressors and stressor‐related negative emotions. A diverse community sample of 255 adults (age 25–65 years) completed ecological momentary assessments (EMA), during which they reported recent stressors and current negative affect (NA) five times a day for 14 days. Multilevel logistic analyses indicated that there was a quadratic association between loneliness and likelihood of reporting stressors, controlling for demographics, social isolation, depressive symptoms, and context (current activities, current location). Multilevel regression indicated that loneliness was unrelated to the concurrent effect of stressors on NA but significantly larger lagged stressor effects were observed among individuals in the low and high ranges of loneliness. These findings suggest that individuals with high levels of loneliness are more likely to experience everyday stressors and have prolonged emotional responses following stressors.