Caring for children and/or relatives while working at the same time and in the same space, lack of movement and physical meetings in times of lockdowns and with increasing digitization, suboptimal workplace ergonomics, job insecurity are just a few of the recent stressors. Nevertheless, when it comes to the predictors of workplace stress, job demands rather than the resources seemed to be responsible for psychological distress during the pandemic [1]. Working from home places demands on employees, which in turn have both positive and negative effects on stress [2]. In terms of work organization, there might be individual advantages, such as the elimination of commuting or improvement of time management. However, communication within organizations still lacks clear structures for working from home. The pandemic situation has accelerated e.g. the ministry's plans to digitalize the work of public administrations in North Rhine Westphalia, Germany [3]. The conditions coming along with the pandemic provided the opportunity to examine the temporal variation of mental strain in the setting.
Mental stress and mental strain
In May 2020, the World Health Organization described the impact of the COVID-19 pandemic on mental health as "highly worrying" [4]. Psychological fragility caused to human life is supposed to be the largest aftermath of the pandemic posing a raised public health concern globally. This psychological impact is i.a. identified as Post-Traumatic Stress Disorder (PTSD) which was the most commonly diagnosed psychological disorder during this pandemic [5]. If left unidentified this condition can be accompanied by multiple comorbidities and take a transformation into psychic dysfunctions.
According to DIN EN ISO 10075-1, mental stress is defined as the "totality of all detectable influences that come from outside and affect a person psychologically" [6, 7]. Mental (or syn. psychological) strain is understood as the corresponding immediate, but not long-term, effect of mental stress in the individual. Due to the possible positive as well as negative effects of mental strain and stress in the workplace, both terms are formulated neutrally [6, 8]. Stress and strain lead to long-term stress consequences, which are the long-term effects of mental strain in the individual, whereby this chain of effects is also dependent on the characteristics of the affected individual [8]. The consequences of the chain of effects can include, on the one hand, stimulating effects, such as further development of abilities or health, and, on the other hand, impairing effects, such as the occurrence of psychosomatic illnesses or early retirement [8].
The biopsychosocial model [9] is a fundamental theory of the body-mind unit and enables a holistic understanding of illness or health. Thoughts and feelings are not only mental, but always at the same time also physical events that belong to the same process, even if they appear as distinguishable phenomena and are described in two different language systems. With this approach, the logical and empirical-scientific problem of "psychosomatics" that has persisted for centuries can be solved to some extent on a systems-theoretical (and semiotic) basis [10]. Nixon et al. [11] outline the psychosomatic effects of workplace stressors, i.e. organizational constraints, such as interpersonal conflict, role conflict, role ambiguity, workload, work hours and lack of control. All of these occupational stressors are significantly related to physical symptoms. Gastrointestinal complaints and sleep disturbances are significantly associated with more stressors than the other symptoms studied. In the biopsychosocial model, illness and health are not defined as a state, but as a dynamic process, i.e. Salutogenesis [12]; health must be "created" at all times. Therefore, illness occurs when the organism cannot sufficiently provide the auto-regulative competence to cope with occurring disturbances on any level of the system "human being" and relevant control circuits for the functioning of the individual are overstrained or fail.
In the short term, stress can be beneficial to health [8]. If the stressor has a stimulating, positive function it is referred to as eustress (e.g., motivation, feeling of happiness). It becomes harmful if the short-term activation cannot be compensated or coped with. Stressors that are perceived as unpleasant or overwhelming have a negative function, speaking of distress (e.g. despair, pain). Distress brings a strongly increased tension of the body, which, for example, leads to a decrease of attention and performance [13].
Knight et al. [1] reveal two pandemic-related mental distress profiles for employees: (i) a declining distress profile where employees experienced reduced distress over time, suggesting adaptation and/or improved coping; (ii) a rising distress profile where distress increased and eventually plateaued, suggesting a stress reaction process followed by adaptation. Employees with high workload, underload, or close monitoring, are more likely to belong to the rising distress profile [1]. Detachment from work buffers the negative effect of workload and close monitoring on distress profile membership. Scheduling autonomy and colleague support do not predict profile membership. Contrary to predictions, manager support is associated with membership in the rising distress profile. Further research indicates that perceived stress is negatively associated with job performance and this relation is mediated by psychological distress [13]. In the context of a crisis which can cause considerable stress, such as the COVID-19 pandemic, health-promoting management practices can buffer the deleterious effect of perceived stress on psychological health and job performance.
In today's PAID (Pressure, Always-on, Information overload, Distracted) reality [14], stress has emerged to be an integral part of everyone's life which affects an individual directly or indirectly in many ways. The COVID-19 pandemic even enhanced the cruciality of managing stress, as it created a massive impact on the economy, education, healthcare, business areas and other aspects of society in every possible manner [15]. Specifically, the employees' emotional reactions are elicited from the perceived organizational support, in how organization cares for their well-being and work contributions and, in turn, influence the psychological safety. For instance, the approach of online communication practiced by managers has implications on the different levels of psychological safety experienced by the employee [16].
Absenteeism due to mental disorders during the pandemic
Looking at health reports by social insurers for the reporting year 2020, the first thing that stands out is that the cases of incapacity for work due to mental disorders were on the decline [17]. Thus, there were fewer documented new mental illnesses, which can potentially be attributed to underdiagnosis, especially during lockdown phases. In contrast, days of sick leave in the pandemic year 2020 increased compared to the previous year 2019, which could indicate an aggravation of prevalent cases. Mental illnesses were responsible for a total of 17.5 per cent of all days of sick leave, making them the second most common cause of incapacity for work after musculoskeletal complaints. This corresponds to the second most sickness benefit cases (20 %)and the most sickness benefit days (28.7 %) which is due to the constantly high duration of mental illness cases with 43.4 days on average. Within this group of illnesses, the more serious cases dominated. The most important diagnoses were "reactions to severe stress and adjustment disorders" (F43 in ICD-10-GM; 2.56 cases and 77.3 days per 100 insured persons, 30.2 days average case duration) and depressive episodes (0.5 cases and 39.1 days, 78.9 days case duration). The significance of mental illnesses increased monotonously up to retirement age. A clear frequency peak was found in the 60–64 age group. In all age groups, women appear to be more frequently affected by mental illnesses, while musculoskeletal disorders dominate among male employees. Burnout syndrome (Z73 in ICD-10-GM) is not recognized as an independent disorder, but corresponds to an additional diagnosis. In a year-on-year comparison, the number of cases per 100 insured persons also decreased. The case duration per 100 insured persons was increasing for female employees (95 versus 104 days) and constant for male employees (61 days). Due to the high comorbidity and misclassification rate of burnout, a high proportion of those suffering from a depressive disorder in addition or instead can be assumed.
Absence periods reports by the social insurers, state equal trends and emphasize the increased burden on the tertiary and especially the health sector [18]. In there, reference is made to a publication, which, based on a convenience sample beyond the world of work, finds that generalized anxiety, symptoms of major depression and psychological distress were permanently elevated over the entire survey period (March to July 2020) compared to pre-pandemic levels [19]. It is noteworthy that the course of the pandemic as well as the decrease in the number of cases in the phase of the "new normality" (May to July 2020) had no influence on these outcomes. In contrast, the fear of a COVID-19 infection correlated clearly with these phases of different incidence and thus with the actual risk of infection. Consequently, the increased psychological strain during the pandemic might have been mainly not due to fear of infection. It can be assumed that the absenteeism report underestimates the actual prevalence because many employees may have avoided going to medical care due to fear of infection or uncertainty about the security of care.
In summary, it can be said that in 2020 there was not yet an increase in cases of mental illness among workers caused by the pandemic. At the same time, however, an aggravation of existing disorders, especially more serious ones, was evident.
Initial data for the reporting year 2021 indicate that the mental health effects of the pandemic are reflected in the incapacity to work statistics, albeit with a delay, but now recognizably [20]. It no longer only records an increase in days of incapacity for work due to mental illness. Meanwhile, an increase in the number of cases of sick leave can also be observed; probably slowly approaching the actual prevalence.
Hypothesis; socio-demographic and psychosomatic correlates of mental strain
The COVIDiSTRESS Global Survey data reveals that higher levels of strain are associated with younger age, being a woman, lower level of education, being single, staying with more children [21].
Competing interpretations exist regarding the impact of multiple roles, such as having children, on psychological distress. Greater role involvement is associated with greater well-being; however, only well educated women with multiple roles show higher levels of autonomy [22]. Women form a more vulnerable population group with regard to mental health impairments, as women suffer more frequently from mental disorders and are more prone to emotional exhaustion [23, 24]. Biopsychosocial explanations include higher sensitivity and differences in reporting behaviors, and, additionally, women evaluate negative health consequences more strongly [25]. Female employees are more likely than their male counterparts to experience resource loss due to work-family interference and demanding household chores when working from home [26]. Another pandemic consequence that is directly related to the mental strain of working women is an increased adherence to traditional gender roles and in some places even regressions in the sense of a re-traditionalization [27]. This can be attributed to the fact that "proven" behavior patterns are increasingly used in new emerging, potentially dangerous situations.
Perhaps the gravest restrictions of the COVID-19 pandemic was social isolation [28, 29]. In Kettschau et al. [30] it is discussed that more than half of the administrative employees are overweight, which is regarded to as a risk factor for physical complaints. Overweight individuals are predictive of weight gain [31], exercise avoidance [32], emotional eating [33], and non-optimal mental health [34]. Furthermore, individuals with obesity are already at higher risk of social isolation [31, 35]. Moreover, weight management may have been especially difficult during the COVID-19 pandemic, as reduced in-person support, less physical activity options, daily routine disruption, and food-focused coping are all associated with weight gain [36, 37]. The majority of participants enrolled in a behavioral weight loss program gained weight during the COVID-19 pandemic. Loneliness and working remotely predicted difficulty engaging in weight-related health behaviors [38].
While civil service mostly counts as secure (i.e. job security and social security benefits), modernization and digitalization in the administrative profession is a challenge. In German public administration, work stress is reported due to restructuring measures, staff shortage, workload, the aging of the workforce, as well as low employee participation and few opportunities for relief at work [39]. The organization of the departments and the work processes are a major cause of stress, while the interventions mostly address individual behavior rather than performance and organizational aspects. Wrede et al. [40] found that within the setting having relatives to care for is a significant risk factor for digital stress.
We contribute this work to investigate on how mental strain progressed within the setting in 2020–2022? With regard to the current literature, we assume that psychological strain differs from the first to the second time of the survey.