Social mobile sensing and problematic alcohol consumption: Insights from smartphone metadata.

BACKGROUND: Alcohol is often consumed in a social context. We aim to investigate whether social mobile sensing is associated with real-world social interactions and alcohol consumption. In addition, we investigate how social restriction policies implemented during the COVID-19 pandemic have influenced these associations. METHODS: We conducted a smartphone-based ecological momentary assessment (EMA) study for 7 days over a 213-day period from 8 August 2020 to 9 March 2021 in Germany, including both no-lockdown and lockdown stages. Participants used a smartphone application which passively collects data on social behavior (e.g., app usage, phone calls, SMS). Moreover, we assessed real-world social interactions and alcohol consumption via daily questionnaires. RESULTS: We found that each one-hour increase in social media usage was associated with a 40.2% decrease in the average number of drinks consumed. Mediation analysis suggested that social media usage decreases alcohol intake through decreased real-world social interactions. Notably, we did not find that any significant influence of the lockdown stage on the association between social mobile sensing and alcohol intake. CONCLUSIONS: Our study suggests that people who use more social media drink less, likely due to reduced face-to-face social interactions. This highlights the potential of social mobile sensing as an objective measure of social activity and its implications for understanding alcohol consumption behavior.

Heart rate and heart rate variability in obsessive-compulsive disorder: Evidence from patients and unaffected first-degree relatives.

Altered heart rate (HR) and heart rate variability (HRV) are common observations in psychiatric disorders. Yet, few studies have examined these cardiac measures in obsessive-compulsive disorder (OCD). The current study aimed to investigate HR and HRV, indexed by the root mean square of successive differences (RMSSD) and further time domain indices, as putative biological characteristics of OCD. Electrocardiogram was recorded during a five-minute resting state. Group differences between patients with OCD (n = 96), healthy participants (n = 112), and unaffected first-degree relatives of patients with OCD (n = 47) were analyzed. As potential moderators of group differences, we examined the influence of age and medication, respectively. As results indicated, patients with OCD showed higher HR and lower HRV compared to healthy participants. These group differences were not moderated by age. Importantly, subgroup analyses showed that only medicated patients displayed lower HRV compared to healthy individuals, while HR alterations were evident in unmedicated patients. Regarding unaffected first-degree relatives, group differences in HRV remained at trend level. Further, an age-moderated group differentiation showed that higher HRV distinguished relatives from healthy individuals in young adulthood, whereas at higher age lower HRV was indicative of relatives. Both the role of familial risk and medication in HRV alterations need further elucidation. Pending future studies, alterations in HR and potentially HRV might serve as useful indices to characterize the pathophysiology of OCD.

High-mind wandering correlates with high risk for problematic alcohol use in China and Germany.

Everyone experiences the natural ebb and flow of task-unrelated thoughts. Given how common the fluctuations in these thoughts are, surprisingly, we know very little about how they shape individuals' responses to alcohol use. Here, we investigated if mind wandering is associated with a risk of developing problematic alcohol use. We undertook an online survey among the general population in China (N = 1123) and Germany (N = 1018) from December 2021 to February 2022 and examined the subjective experience of mind wandering and problematic alcohol use through the Mind Wandering Questionnaire (MWQ) and the Alcohol Use Disorders Identification Test (AUDIT). We compared mind wandering and problematic alcohol use between two countries and investigated the association between MWQ scores with AUDIT scores. We found higher scores on the MWQ and a high percentage of problematic alcohol use (i.e., AUDIT score ≥ 8) in Germany (22.5%) as compared to in China (14.5%). Higher self-reported mind wandering was associated with higher AUDIT scores. AUDIT scores were increased mostly in male, elder, and high-mind wandering people. Our findings highlight that mind wandering and problematic alcohol use enhanced in Germany as compared to in China. Our study sheds light on the relationship between mind wandering and problematic alcohol use that may help to further investigate causal effects of interventions.

Involuntary social isolation and alcohol consumption: an ecological momentary assessment in Germany amid the COVID-19 pandemic.

AIMS: Alcohol consumption often occurs in a social setting, which was affected by social distancing measures amid the coronavirus disease-2019 (COVID-19) pandemic. In this study, we examine how involuntary social isolation (i.e. comparing a no-lockdown stage with a lockdown stage) affects the association between loneliness, social activities, and drinking behavior. METHOD: We performed an ecological momentary assessment eight times per day for 7 days amid the COVID-19 pandemic in Germany. We recruited 280 participants and assessed their trait loneliness, daily state loneliness, social activities, and drinking behaviors. RESULTS: We found that a lockdown condition moderates the association between trait and daily state loneliness and alcohol consumption. During a lockdown stage, trait loneliness was positively associated, whereas state loneliness was negatively associated with alcohol consumption. During a no-lockdown stage, trait and state loneliness were both negatively associated with alcohol consumption. For both no-lockdown and lockdown stages, duration of social interaction, male gender, and weekends was positively associated with alcohol consumption. CONCLUSION: Our study suggests that an involuntary social isolation condition (i.e. a lockdown stage) changes how trait loneliness is associated with alcohol consumption.

Effect of acute and long-term exercise on leptin levels in depressed outpatients.

BACKGROUND: Depression is a leading cause of disability worldwide and a significant contributor to the global burden of disease. Altered leptin levels are known to be associated with depressive symptoms, however discrepancies in the results of increased or decreased levels exist. Due to various limitations associated with commonly used antidepressant drugs, alternatives such as exercise therapy are gaining more importance. Therefore, the current study investigates whether depressed patients have higher leptin levels compared to healthy controls and if exercise is efficient to reduce these levels. METHODS: Leptin levels of 105 participants with major depressive disorder (MDD; 45.7% female, age mean ± SEM: 39.1 ± 1.0) and 34 healthy controls (HC; 61.8% female, age mean ± SEM: 36.0 ± 2.0) were measured before and after a bicycle ergometer test. Additionally, the MDD group was separated into three groups: two endurance exercise intervention groups (EX) differing in their intensities, and a waiting list control group (WL). Leptin levels were measured pre and post a 12-week exercise intervention or the waiting period. RESULTS: Baseline data showed no significant differences in leptin levels between the MDD and HC groups. As expected, correlation analyses displayed significant relations between leptin levels and body weight (HC: r = 0.474, p = 0.005; MDD: r = 0.198, p = 0.043) and even more with body fat content (HC: r = 0.755, p < 0.001; MDD: r = 0.675, p < 0.001). The acute effect of the bicycle ergometer test and the 12-week training intervention showed no significant changes in circulating leptin levels. CONCLUSION: Leptin levels were not altered in patients with major depression compared to healthy controls and exercise, both the acute response and after 12 weeks of endurance training, had no effect on the change in leptin levels. TRIAL REGISTRATION: The study was registered at the German register for clinical studies (DRKS) and the International Clinical Trials Registry Platform of the World Health Organization https://trialsearch.who.int/Trial2.aspx?TrialID=DRKS00008869 on 28/07/2015.

Anxiety in response to the climate and environmental crises: validation of the Hogg Eco-Anxiety Scale in Germany.

Background: As the climate and environmental crises unfold, eco-anxiety, defined as anxiety about the crises' devastating consequences for life on earth, affects mental health worldwide. Despite its importance, research on eco-anxiety is currently limited by a lack of validated assessment instruments available in different languages. Recently, Hogg and colleagues proposed a multidimensional approach to assess eco-anxiety. Here, we aim to translate the original English Hogg Eco-Anxiety Scale (HEAS) into German and to assess its reliability and validity in a German sample. Methods: Following the TRAPD (translation, review, adjudication, pre-test, documentation) approach, we translated the original English scale into German. In total, 486 participants completed the German HEAS. We used Bayesian confirmatory factor analysis (CFA) to assess whether the four-factorial model of the original English version could be replicated in the German sample. Furthermore, associations with a variety of emotional reactions towards the climate crisis, general depression, anxiety, and stress were investigated. Results: The German HEAS was internally consistent (Cronbach's alphas 0.71-0.86) and the Bayesian CFA showed that model fit was best for the four-factorial model, comparable to the factorial structure of the original English scale (affective symptoms, rumination, behavioral symptoms, anxiety about personal impact). Weak to moderate associations were found with negative emotional reactions towards the climate crisis and with general depression, anxiety, and stress. Discussion: Our results support the original four-factorial model of the scale and indicate that the German HEAS is a reliable and valid scale to assess eco-anxiety in German speaking populations.

The influence of perceived stress and income on mental health in China and Germany.

Background: Mental health issues affect rich and poor, young and old, and are widespread in Asia as well as in Europe. However, few studies have investigated the influence of perceived stress and income on mental health among general population in China and in Germany. Methods: We conducted an online survey from December 2021 to February 2022 to investigate how perceived stress and income affect mental health among the general population in China (N = 1123) and in Germany (N = 1018). Accordingly, we used the 10-item Perceived Stress Scale (PSS-10) and the 12-item General Health Questionnaire (GHQ-12). We ran a multiple linear regression model to investigate the relationship between perceived stress, income, and mental health. Results: Overall, we found that 53.4% participants reported mental health issues (GHQ-12 score ≥12). The proportion of our sample who reported mental health issues was higher in Germany (60.3%) than in China (44.8%). The regression model revealed that a higher perceived stress score was associated with more mental health issues in both countries (b = 0.60, p < 0.01). Individuals with a low income reported poorer mental health in Germany than those in China. Interestingly, the situation was reversed when incomes were high: individuals with a high income reported worse mental health in China than in Germany (b = -0.40, p < 0.01). Conclusion: Perceived stress has a negative impact on mental health, while income has differential effects. Mental health promotion programmes may involve teaching stress management, while considering differences in mental health outcomes in developed and developing countries.

Self-Esteem Mediates the Effects of Loneliness on Problematic Alcohol Use.

Loneliness has been associated with problematic alcohol use, but it is not known whether self-perceptions mediate this relationship. In this study, the general population in China (N = 1123) and Germany (N = 1018) was surveyed to assess whether self-esteem and self-efficacy mediate the effect of loneliness on problematic alcohol use in two culturally distinct environments. Multiple regression analysis demonstrated that higher AUDIT scores were negatively associated with self-esteem (b = -0.08, p < .001). Self-esteem mediated the effect of loneliness on AUDIT score (indirect effect: 0.06, CI: 0.03 - 0.10, p < .001), while self-efficacy did not (indirect effect: 0.02, CI: -0.003 - 0.05, p = .10). These findings suggest that self-esteem explains the relationship between loneliness and problematic alcohol use. As self-esteem may be more modifiable than external social factors, these results have positive practical implications for alcohol use disorder treatment strategies.

Negative and positive self-beliefs in social anxiety: The strength of believing mediates the affective response.

BACKGROUND AND OBJECTIVES: Current cognitive models of social anxiety disorder (SAD) propose that individual, situation-specific self-beliefs are central to SAD. However, the role of differences in the degree to which individuals with social anxiety are convinced of self-beliefs, in particular positive ones, is still not fully understood. We compared how much high and low socially anxious individuals agree with their own negative and positive self-beliefs. Furthermore, we investigated whether agreeing with one's self-belief can explain the relation between negative affect in response to self-beliefs and social anxiety. Specifically, we were interested whether social anxiety increases negative affect in response to self-beliefs through an increase in agreement. METHODS: We developed a new experimental self-belief task containing positive and negative semi-idiosyncratic, situation specific self-beliefs typical of high social anxiety and included a direct measure of agreement with these beliefs. Using extreme group sampling, we a-priori selected high (n = 51) and low (n = 50) socially anxious individuals. By multi-level mediation analysis, we analyzed agreement with self-beliefs in both groups and its association with affect. RESULTS: High and low socially anxious individuals chose similar self-beliefs. However, high socially anxious individuals (HSA) agreed more with negative self-beliefs and less with positive self-beliefs compared to low socially anxious individuals (LSA). HSA individuals reported increased negative affect after both, exposition to negative and positive self-beliefs compared to LSA. We found that social anxiety increases affective responses towards negative-self beliefs through an increase in agreeing with these self-beliefs. CONCLUSIONS: These findings suggest that cognitive models of social anxiety can be improved by including not only the content of a self-belief but also the strength of such a belief. In addition, they emphasize the relevance of positive self-beliefs in social anxiety, which has frequently been overlooked.

Error-Related Brain Activity in Patients With Obsessive-Compulsive Disorder and Unaffected First-Degree Relatives: Evidence for Protective Patterns.

Background: Indicators of increased error monitoring are associated with obsessive-compulsive disorder (OCD), as shown in electroencephalography and functional magnetic resonance imaging studies. As most studies used strictly controlled samples (excluding comorbidity and medication), it remains open whether these findings extend to naturalistic settings. Thus, we assessed error-related brain activity in a large, naturalistic OCD sample. We also explored which activity patterns might qualify as vulnerability endophenotypes or protective factors for the disorder. To this aim, a sample of unaffected first-degree relatives of patients with OCD was also included. Methods: Participants (84 patients with OCD, 99 healthy control participants, and 37 unaffected first-degree relatives of patients with OCD) completed a flanker task while blood oxygen level-dependent responses were measured with functional magnetic resonance imaging. Aberrant error-related brain activity in patients and relatives was identified. Results: Patients with OCD showed increased error-related activity in the supplementary motor area and within the default mode network, specifically in the precuneus and postcentral gyrus. Unaffected first-degree relatives showed increased error-related activity in the bilateral inferior frontal gyrus. Conclusions: Increased supplementary motor area and default mode network activity in patients with OCD replicates previous studies and might indicate excessive error signals and increased self-referential error processing. Increased activity of the inferior frontal gyrus in relatives may reflect increased inhibition. Impaired response inhibition in OCD has been demonstrated in several studies and might contribute to impairments in suppressing compulsive actions. Thus, increased inferior frontal gyrus activity in the unaffected relatives of patients with OCD may have contributed to protection from symptom development.

Effects of a three-week executive control training on adaptation to task difficulty and emotional interference.

Intact executive functions are characterized by flexible adaptation to task requirements, while these effects are reduced in internalizing disorders. Furthermore, as executive functions play an important role in emotion regulation, deficits in executive functions may contribute to symptom generation in psychological disorders through increased emotional interference. Thus, the present study investigated transfer effects of a three-week executive control training on adaptation to task difficulty and emotional interference in healthy participants (n = 24) to further explore the training's suitability for clinical application. To assess the adaptation to task difficulty, the proportion congruency effect on behavioral data (response times, error rates) and ERP measures (N2, CRN) was assessed in a flanker task with varying frequency of incompatible trials (25%, 75%). To quantify emotional interference, flanker stimuli were superimposed on neutral or negative pictures. Replicating previous results, the training increased interference control as indexed by decreased response times and errors rates, increased N2 amplitude and decreased CRN amplitude in incompatible trials after training. Proportion congruency effects were weaker than expected and not affected by the training intervention. The training lead to a shift in the time-point of emotional interference: before training negative pictures lead to a reduction in CRN amplitude, while after training this reduction was observed for the N2. This pattern illustrates that the training leads to a change in task processing mode from predominant response-related cognitive control to predominant stimulus-related cognitive control (N2), indicating a proactive processing mode.

Basic psychological need satisfaction and frustration in major depressive disorder.

Basic psychological needs theory postulates that a social environment that satisfies individuals' three basic psychological needs of autonomy, competence, and relatedness leads to optimal growth and well-being. On the other hand, the frustration of these needs is associated with ill-being and depressive symptoms foremost investigated in non-clinical samples; yet, there is a paucity of research on need frustration in clinical samples. Survey data were compared between adult individuals with major depressive disorder (MDD; n = 115; 48.69% female; 38.46 years, SD = 10.46) with those of a non-depressed comparison sample (n = 201; 53.23% female; 30.16 years, SD = 12.81). Need profiles were examined with a linear mixed model (LMM). Individuals with depression reported higher levels of frustration and lower levels of satisfaction in relation to the three basic psychological needs when compared to non-depressed adults. The difference between depressed and non-depressed groups was significantly larger for frustration than satisfaction regarding the needs for relatedness and competence. LMM correlation parameters confirmed the expected positive correlation between the three needs. This is the first study showing substantial differences in need-based experiences between depressed and non-depressed adults. The results confirm basic assumptions of the self-determination theory and have preliminary implications in tailoring therapy for depression.

Modality-specific effects of mental fatigue in multitasking.

The mechanisms underlying increased dual-task costs in the comparison of modality compatible stimulus-response mappings (e.g., visual-manual, auditory-vocal) and modality incompatible mappings (e.g., visual-vocal, auditory-manual) remain elusive. To investigate whether additional control mechanisms are at work in simultaneously processing two modality incompatible mappings, we applied a transfer logic between both types of dual-task mappings in the context of a mental fatigue induction. We expected an increase in dual-task costs for both modality mappings after a fatigue induction with modality compatible tasks. In contrast, we expected an additional, selective increase in modality incompatible dual-task costs after a fatigue induction with modality incompatible tasks. We tested a group of 45young individuals (19-30 years) in an online pre-post design, in which participants were assigned to one of three groups. The two fatigue groups completed a 90-min time-on-task intervention with a dual task comprising either compatible or incompatible modality mappings. The third group paused for 90 min as a passive control group. Pre and post-session contained single and dual tasks in both modality mappings for all participants. In addition to behavioral performance measurements, seven subjective items (effort, focus, subjective fatigue, motivation, frustration, mental and physical capacity) were analyzed. Mean dual-task performance during and after the intervention indicated a practice effect instead of the presumed fatigue effect for all three groups. The modality incompatible intervention group showed a selective performance improvement for the modality incompatible mapping but no transfer to the modality compatible dual task. In contrast, the compatible intervention group showed moderately improved performance in both modality mappings. Still, participants reported increased subjective fatigue and reduced motivation after the fatigue intervention. This dynamic interplay of training and fatigue effects suggests that high control demands were involved in the prolonged performance of a modality incompatible dual task, which are separable from modality compatible dual-task demands.

Error-related activity of the sensorimotor network contributes to the prediction of response to cognitive-behavioral therapy in obsessive-compulsive disorder.

BACKGROUND: Although cognitive behavioral therapy is a highly effective treatment for obsessive-compulsive disorder (OCD), yielding large symptom reductions on the group level, individual treatment response varies considerably. Identification of treatment response predictors may provide important information for maximizing individual treatment response and thus achieving efficient treatment resource allocation. Here, we investigated the predictive value of previously identified biomarkers of OCD, namely the error-related activity of the supplementary motor area (SMA) and the sensorimotor network (SMN, postcentral gyrus/precuneus). METHODS: Seventy-two participants with a primary diagnosis of OCD underwent functional magnetic resonance imaging (fMRI) scanning while performing a flanker task prior to receiving routine-care CBT. RESULTS: Error-related BOLD response of the SMN significantly contributed to the prediction of treatment response beyond the variance accounted for by clinical and sociodemographic variables. Stronger error-related SMN activity at baseline was associated with a higher likelihood of treatment response. CONCLUSIONS: The present results illustrate that the inclusion of error-related SMN activity can significantly increase treatment response prediction quality in OCD. Stronger error-related activity of the SMN may reflect the ability to activate symptom-relevant processing networks and may thus facilitate response to exposure-based CBT interventions.

Physical exercise training as preceding treatment to cognitive behavioral therapy in mild to moderate major depressive disorder: A randomized controlled trial.

BACKGROUND: Many patients with major depressive disorder (MDD) remain untreated or do not respond to cognitive behavioral therapy (CBT). Physical exercise shows antidepressive effects and may serve as an effective augmentation treatment. However, research on combining exercise with CBT is sparse in MDD and underlying mechanisms of exercise are not well understood to date. METHODS: 120 outpatients with MDD were randomized to either a high intensity exercise group (HEX), a low intensity exercise group (LEX), or a waiting list control group (WL). After 12 weeks of exercise training or waiting period, all patients received a manualized CBT. RESULTS: Seventy-five patients with MDD completed both the exercise program/ waiting period and the CBT. While physical fitness improved in HEX after the exercise program, it did not change in LEX and WL. Depressive symptoms improved in all three groups from baseline to post-CBT and the group by time interaction was not significant. Regression analyses revealed that the amount of fitness improvement during exercise predicted the subsequent CBT response. LIMITATIONS: The dropout rate was relatively high, preparatory CBT sessions during exercise / waiting period may have influenced depressive symptoms, and no patients with severe MDD were included. CONCLUSIONS: High intense physical exercise did not lead to a general enhancement of CBT outcome, but higher increases in physical fitness seem to improve symptom change during CBT. Our results suggest that the implementation of more individually tailored exercise programs could be a promising approach for future research and clinical practice.

The effects of momentary loneliness and COVID-19 stressors on hypothalamic-pituitary adrenal (HPA) axis functioning: A lockdown stage changes the association between loneliness and salivary cortisol.

The COVID-19 pandemic can be characterized as a chronic stressor affecting the hypothalamic-pituitary-adrenal (HPA) axis, indexed by glucocorticoids (e.g., cortisol). We investigated whether salivary cortisol level is increased during a lockdown and whether a lockdown condition affects the association between loneliness, specific COVID-19 related stressors and salivary cortisol level. We conducted a smartphone-based ecological momentary assessment (EMA) study with 280 participants in Germany who experienced at least mild loneliness and distress amid COVID-19 from August 2020 to March 2021. We measured their momentary loneliness and COVID-related stressors including worries, information seeking behaviors and feelings of restriction during "no-lockdown" or "lockdown" stages amid COVID-19. Their salivary cortisol was measured 4 times on the last day of a 7-day EMA study. We found a significant increase in salivary cortisol levels during lockdown compared to no-lockdown. Lockdown stage was found to moderate the relationship between momentary loneliness and salivary cortisol level, i.e., loneliness was positively related to cortisol level specifically during lockdown. Mechanisms explaining the effect of forced social isolation on the association between loneliness and salivary cortisol need to be investigated in future studies.

Evaluating the Public Climate School-A School-Based Programme to Promote Climate Awareness and Action in Students: Protocol of a Cluster-Controlled Pilot Study.

Introduction: School-based programmes may promote knowledge and skills required to address climate change and better health and well-being in adolescents, yet evidence of their effectiveness is limited. In preparation for evaluating the Public Climate School, a school-based intervention to promote climate awareness and action in adolescents, we conduct a pilot study intended to assess procedures for participant recruitment, retention, and data collection, data quality issues and to provide preliminary parameter estimates to guide sample size calculations. Methods and analysis: This unblinded, cluster-controlled pilot study targets students in twelve classes from grades seven to thirteen in German public schools. Seven and five classes were allocated to the intervention and waitlist control arms, respectively. The intervention consisted of (1) live lessons on YouTube, (2) climate-related challenges of the day, (3) workshops and (4) peer exchange sessions. Waitlist control classes participated three weeks later. Measures included the proportion of students completing baseline and follow-up surveys, a comparison of baseline characteristics between students in the retained subsample and those lost to follow-up, proportions of students completing online and paper-pencil-based surveys and problems during data collection based on information reported by teachers. Data quality was assessed as proportions of missing data, associations between missingness and sociodemographic measures using logistic regression models and basic psychometric properties of scales including ceiling effects and internal consistency. Intentions to reduce one's ecological footprint, the primary outcome, and all secondary outcomes for effect estimation were assessed one week pre- and post-intervention from November to December 2021 using items adapted from internationally used instruments and will be investigated using generalised linear mixed models and intention-to-treat analyses. Conclusions: The pilot study will lay the methodological groundwork for a large-scale cluster-randomised effectiveness and process evaluation of the Public Climate School. If proven effective and rolled out more broadly, the Public Climate School has the potential to contribute meaningfully to national climate mitigation and adaptation efforts by reaching a substantial share of adolescents in public schools, including those traditionally less involved in climate action.

Smartphone-Based Ecological Momentary Assessment of Coping with Loneliness amid COVID-19 in Germany.

The COVID-19 pandemic may have caused people to feel isolated, left out, and in need of companionship. Effective strategies to cope with such unrelenting feelings of loneliness are needed. In times of COVID-19, we conducted a smartphone-based ecological momentary assessment (EMA) study with 280 lonely participants in Germany over 7 months, where a long and hard second national lockdown was in place. Each participant reported their daily loneliness and coping strategies for loneliness once in the evening for 7 consecutive days. We found that managing emotions and social relationships were associated with decreased feelings of loneliness, while using a problem-focused coping strategy was associated with increased feelings of loneliness amid COVID-19. Interestingly, managing emotions was particularly effective for easing loneliness during the second lockdown. Females tend to use more emotion-focused coping strategies to overcome their loneliness compared to males. Our study highlights the importance of managing emotions against loneliness throughout the COVID-19 pandemic in Germany. Designing technology that provides emotional support to people may be one of the keys to easing loneliness and promoting well-being.

The acute effects of mental fatigue on balance performance in healthy young and older adults - A systematic review and meta-analysis.

Cognitive resources contribute to balance control. There is evidence that mental fatigue reduces cognitive resources and impairs balance performance, particularly in older adults and when balance tasks are complex, for example when trying to walk or stand while concurrently performing a secondary cognitive task. We conducted a systematic literature search in PubMed (MEDLINE), Web of Science and Google Scholar to identify eligible studies and performed a random effects meta-analysis to quantify the effects of experimentally induced mental fatigue on balance performance in healthy adults. Subgroup analyses were computed for age (healthy young vs. healthy older adults) and balance task complexity (balance tasks with high complexity vs. balance tasks with low complexity) to examine the moderating effects of these factors on fatigue-mediated balance performance. We identified 7 eligible studies with 9 study groups and 206 participants. Analysis revealed that performing a prolonged cognitive task had a small but significant effect (SMDwm = -0.38) on subsequent balance performance in healthy young and older adults. However, age- and task-related differences in balance responses to fatigue could not be confirmed statistically. Overall, aggregation of the available literature indicates that mental fatigue generally reduces balance in healthy adults. However, interactions between cognitive resource reduction, aging and balance task complexity remain elusive.

The Impact of COVID-19 Lockdown on Daily Activities, Cognitions, and Stress in a Lonely and Distressed Population: Temporal Dynamic Network Analysis.

BACKGROUND: The COVID-19 pandemic and its associated lockdown measures impacted mental health worldwide. However, the temporal dynamics of causal factors that modulate mental health during lockdown are not well understood. OBJECTIVE: We aimed to understand how a COVID-19 lockdown changes the temporal dynamics of loneliness and other factors affecting mental health. This is the first study that compares network characteristics between lockdown stages to prioritize mental health intervention targets. METHODS: We combined ecological momentary assessments with wrist-worn motion tracking to investigate the mechanism and changes in network centrality of symptoms and behaviors before and during lockdown. A total of 258 participants who reported at least mild loneliness and distress were assessed 8 times a day for 7 consecutive days over a 213-day period from August 8, 2020, through March 9, 2021, in Germany, covering a "no-lockdown" and a "lockdown" stage. COVID-19-related worry, information-seeking, perceived restriction, and loneliness were assessed by digital visual analog scales ranging from 0 to 100. Social activity was assessed on a 7-point Likert scale, while physical activity was recorded from wrist-worn actigraphy devices. RESULTS: We built a multilevel vector autoregressive model to estimate dynamic networks. To compare network characteristics between a no-lockdown stage and a lockdown stage, we performed permutation tests. During lockdown, loneliness had the highest impact within the network, as indicated by its centrality index (ie, an index to identify variables that have a strong influence on the other variables). Moreover, during lockdown, the centrality of loneliness significantly increased. Physical activity contributed to a decrease in loneliness amid the lockdown stage. CONCLUSIONS: The COVID-19 lockdown increased the central role of loneliness in triggering stress-related behaviors and cognition. Our study indicates that loneliness should be prioritized in mental health interventions during lockdown. Moreover, physical activity can serve as a buffer for loneliness amid social restrictions.