**1. Introduction**

Satisfaction with life can be defined as the global cognitive self-judgment of wellbeing across a broad set of human activities at school, work, with family, and in social life [1]. Life satisfaction is considered a significant predictor of mental and physical health and successful adaptation to life [2–5]. Research indicates that higher levels of perceived stress are related to decreased levels of life satisfaction [4,6–14]. Numerous studies reported a decrease in well-being and increases in distress, loneliness, insomnia, anxiety, and depression during the coronavirus outbreak [15–36]. Physical and mental health was found to be a significant positive predictor of life satisfaction during the pandemic [37]. The most desirable skill in a pandemic situation seems to be coping strategies aimed at regulating and reducing negative emotions or pessimistic and unrealistic thinking, as well as solving current problems related to quarantine restrictions, isolation, job loss, deterioration of economic status, and countless lifestyle changes.

In Poland, lockdown started 10–12 March 2020 (with the closing of schools and universities), expanded on 25 March (to limiting non-family gatherings to two people and forbidding non-essential travel), and restrictions tightened on 31 March. Starting from 30

**Citation:** Rogowska, A.M.; Ku´snierz, C.; Ochnik, D. Changes in Stress, Coping Styles, and Life Satisfaction between the First and Second Waves of the COVID-19 Pandemic: A Longitudinal Cross-Lagged Study in a Sample of University Students. *J. Clin. Med.* **2021**, *10*, 4025. https:// doi.org/10.3390/jcm10174025

Academic Editors: Michele Roccella and Emmanuel Andrès

Received: 19 May 2021 Accepted: 3 September 2021 Published: 6 September 2021 Corrected: 5 January 2022

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May 2020, wearing masks in outdoor places was no longer obligatory but was restored as of 10 October 2020 due to the increasing number of cases. Primary lockdown-related stress sources were as follows: isolation, restriction in moving, shopping, traveling, changes in daily lifestyle regards use of face masks, washing hands frequently, avoiding social contact and gatherings, restaurants, pubs, clubs, fitness clubs, limiting physical activity outdoors, and required remote online learning and work [17,38–43].

One of the largest sources of stress was an economic crisis due to prolonged lockdown, which increased concerns about future work-finding and financial stability [18,44]. Lee [45] showed that perceived employment and housing insecurity, deteriorating finances, and difficulties in paying for basic needs predicted life satisfaction, happiness, health selfesteem, mental health index, and mental stress among a large sample of European Union citizens. Remote online learning and academic stress were the risk factors for mental health and decreased well-being of university students before quarantine [46,47] as well as during the pandemic [48–51]. In the present study, university students were examined regarding perceived stress, coping styles, and life satisfaction during the Coronavirus disease 2019 (COVID-19) pandemic.

#### *1.1. Association between Stress, Coping, and Subjective Well-Being*

Coping strategies seem to play a pivotal role in physical and mental health, particularly during adaptation to stressful situations in life [52]. According to the transactional theory of stress [53], stress is understood as a relationship between an individual and their environment, which the person appraises as relevant to their well-being. Stress can emerge when an individual perceives an exceeding of their resources to cope. Lazarus [54] (p. 99) defined coping with stress as "constantly changing cognitive and behavioral efforts to manage specific external and/or internal demands that are appraised as taxing or exceeding the resources of the person". Coping has two main functions: regulating disturbing emotions (aimed at regulating emotional distress) and focusing cognition and behavior on solving the problem that causes distress (aimed at altering person–environment relationships).

Recent international research [55] performed in Russia, Kyrgyzstan, and Peru during the COVID-19 pandemic found that the coping responses related to problem-focused coping, socially supported coping, avoidance, and emotion-oriented coping explained 44% of the coping variability. Significant differences in religious coping and mental disengagement were found across the countries, suggesting that some coping behaviors may play distinct roles in responding to stressful events. Higher psychological distress was associated with more frequent use of passive (negative) coping, but less frequent use of an active (upbeat) coping style during the COVID-19 pandemic [56,57]. There was also an association between coping with stress and subjective well-being. In particular, task-oriented coping style was related positively to well-being, whereas emotion-oriented and avoidance-oriented coping strategies were related negatively [35,58–64].

## *1.2. The Theoretical Background of the Current Study*

Studies from various regions of the world indicate that about 50% of people have experienced high stress levels during the coronavirus pandemic [65–68]. Khodami [24] found that younger people and individuals with a low quality of life were more likely to experience higher stress levels and more significant emotion regulation problems. With increasing quarantine time, quality of life decreased, and perceived stress and emotion regulation problems increased. From a biocultural perspective, financial crisis and prolonged emotional stress during the COVID-19 pandemic may substantially impact growth and development for the next generation, as suggested by Bogin and Varea [69]. Therefore, research on the factors that may decrease stress and elevate well-being in young adults is currently necessary to prepare adequate support, intervention strategies, and prevention programs.

In this study, we examined life satisfaction, stress, and coping style during the coronavirus-related lockdown, considering an intra-individual approach to coping across two stressful situations: the first and second waves of the COVID-19 pandemic. Previous research indicated that university students experience low life satisfaction, high levels of perceived stress, and emotion-oriented coping styles during the first wave of the COVID-19 pandemic [30,70,71]. Life events and coping are intertwined, as reported from studies on the mediating role of coping in the relationship between stress and imminent health consequences [72].

According to the cognitive-transactional model of stress [73], stress results from an interaction between a person and their environment and is subject to continuous change. The meaning of a particular stressful person–environment transaction is derived from the underlying context. Both coping and cognitive appraisals of demands and resources can play a mediating role in the association between experiencing stress and psychological well-being. Coping includes emotional (affective) components that cause physiological changes and have long-term effects concerning mental and somatic health and well-being, and social functioning. The coping strategy is selected as a result of the appraisal process. Lazarus and Folkman [53] suggested that the primary appraisal determines whether a situation is stressful, and a secondary appraisal is initiated to assess the situation, select an appropriate coping strategy, assess the likelihood that a coping option will achieve the expected effect, and whether the person can effectively apply the strategy. In the transactional process, people can continuously reappraise the situation as coping strategies are initiated and the person–environment relationship changes. The short- and long-term health-related outcomes of the process are determined by the selected coping strategy and may vary depending on the setting.

Lardier et al. [74] found a mediating effect of reflective (task-oriented) coping on the relationship between perceived stress and life satisfaction in a cross-sectional study among Hispanic undergraduate students. Reverse mediation analysis, with life satisfaction as a predictor of stress, was also performed [75]. The transactional model of stress [53,73] assumes a one-way relationship from stress (predictor) to life satisfaction (outcome). However, if adverse changes in the outcome (i.e., life satisfaction) are perceived as a stressor, this may trigger a primary appraisal and restart the complete transactional process. Therefore, the inverse model investigated by Gori et al. [75] seems to be equally likely. Here, we examined the interrelationship between stress and life satisfaction and coping styles as mediators of these relationships during the COVID-19 pandemic. Based on the previous studies described above, we formulated the following hypotheses:

**Hypothesis 1 (H1):** *Changes occurred between the first (W1) and second (W2) waves of the COVID-19 pandemic in perceived stress, life satisfaction, and coping styles, as a consequence of stressful person–environment transactional process* [53,73].

**Hypothesis 2 (H2):** *Life satisfaction at W2 may be explained by perceived stress and coping style during W1 and W2 and by life satisfaction measured during W1*.

**Hypothesis 3 (H3):** *Coping styles play a mediating role in the relationship between stress (predictor) and life satisfaction (outcome) during the first (W1) and second (W2) cross-sectional measurements* [74].

**Hypothesis 4 (H4):** *A reciprocal relationship exists between life satisfaction as a predictor and stress as an outcome, and coping styles as mediators, during the first (W1) and second (W2) cross-sectional measurements* [75].

**Hypothesis 5 (H5):** *Because the theory of transactional stress process [53,73] assumes continuous changes in stress and coping, the coping styles during W1 cannot predict either perceived stress during W2 or life satisfaction during W2 using a longitudinal approach*.
