Background More than half of adults in Germany have felt lonely during the COVID-19 pandemic. Previous studies highlight the importance of boosting positive emotions and social connectedness to combat loneliness. However, interventions targeting these protective psychosocial resources remain largely untested. Objective In this study, we aim to test the feasibility of a short animated storytelling video, written messages boosting social connectedness, and a combination of both for alleviating loneliness. Methods We enrolled 252 participants who were 18 years or older and spoke fluent German. Participants were recruited from a previous study on loneliness in Germany. We measured the effects of a combination of an animated video and written messages (intervention A), an animated video (intervention B), and written messages (intervention C) on loneliness, self-esteem, self-efficacy, and hope. We compared these with a control arm, which did not receive any intervention. The animated video was developed by Stanford University School of Medicine to reflect experiences of social isolation during the COVID-19 pandemic and convey messages of hope and solidarity. The written messages communicate four findings from recent studies on loneliness in Germany: (1) over a period of 6 months, 66% of respondents in Germany reported feeling lonely (feelings of loneliness are surprisingly common); (2) physical activity can ease feelings of loneliness; (3) focusing on “what really matters” in one’s life can help to ease feelings of loneliness; and (4) turning to friends for companionship and support can ease feelings of loneliness. Participants were randomized 1:1:1:1 to interventions A, B, C, and the control condition, using the randomization feature of the web-based platform “Unipark,” on which our trial takes place. Both the study investigators and analysts were blinded to the trial assignments. The primary outcome, loneliness, was measured using the short-form UCLA Loneliness Scale (ULS-8). Our secondary outcomes included the scores of the Coping with Loneliness Questionnaire, the 10-item Rosenberg Self-Esteem Scale (RSE), the 10-item General Self-Efficacy Scale, and the 12-item Adult Hope Scale (AHS). Results We observed no statistically significant effect of the tested interventions on loneliness scores, controlling for the baseline loneliness score before an intervention (all P values >.11). However, we observed significantly greater intention to cope with loneliness after exposure to an animated video when compared with the control (β=4.14; t248=1.74; 1-tailed P=.04). Conclusions Our results provide meaningful evidence for the feasibility of a full-scale study. Our study sheds light on the intention to cope with loneliness and explores the potential for creative digital interventions to enhance this psychological precursor, which is integral to overcoming loneliness. Trial Registration German Clinical Trials Register DRKS00027116; https://drks.de/search/en/trial/DRKS00027116

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.

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.

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.

Background If our attention wanders to other thoughts while making a decision, then the decision might not be directed towards future goals, reflecting a lack of model-based decision making, but may instead be driven by habits, reflecting model-free decision making. Here we aimed to investigate if and how model-based versus model-free decision making is reduced by trait spontaneous mind wandering. Methods and findings We used a sequential two-step Markov decision task and a self-report questionnaire assessing trait spontaneous and deliberate mind wandering propensity, to investigate how trait mind wandering relates to model-free as well as model-based decisions. We estimated parameters of a computational neurocognitive dual-control model of decision making. Analyzing estimated model parameters, we found that trait spontaneous mind wandering was related to impaired model-based decisions, while model-free choice stayed unaffected. Conclusions Our findings suggest trait spontaneous mind wandering is associated with impaired model-based decision making, and it may reflect model-based offline replay for other tasks (e.g., real-life goals) outside the current lab situation.