**1. Introduction**

The 2019 coronavirus pandemic (COVID-19) has caused a major health crisis worldwide with a huge psychological impact [1–3]. Regarding health professionals, there is consensus across the literature that they are at increased risk of high stress, anxiety, depression, sleep disorders, burnout and post-traumatic stress disorder, with particular emotional and physical impacts [4–8]. In addition, due to the disruption of the balance between their professional and social lives and the occupational risks associated with exposure to the virus, there is an increase in both physical and mental fatigue [9]. Recent studies have shown that nursing staff have higher rates of emotional symptoms compared to other health professionals [10,11]. Work-related fatigue in nurses has been identified as a threat to their health, but it is also associated with negative consequences for safe and quality patient care [12,13]. Work-related fatigue is a complex and multidimensional condition

**Citation:** Sikaras, C.; Zyga, S.; Tsironi, M.; Tselebis, A.; Pachi, A.; Ilias, I.; Panagiotou, A. The Mediating Role of Depression and of State Anxiety on the Relationship between Trait Anxiety and Fatigue in Nurses during the Pandemic Crisis. *Healthcare* **2023**, *11*, 367. https:// doi.org/10.3390/healthcare11030367

Academic Editors: Florin Oprescu and Alyx Taylor

Received: 15 December 2022 Revised: 24 January 2023 Accepted: 26 January 2023 Published: 28 January 2023

**Copyright:** © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

with emotional, physiological, cognitive, mental and sensory components arising as a consequence of excessive work demands and inadequate energy recovery [13]. Moreover, it is positively correlated with levels of anxiety and depression [12]. Anxiety is one of the most common psychiatric disorders in the general population. It consists of a complex cognitive, emotional, physiological and behavioral response related to preparation for anticipated events or circumstances perceived as threatening [14]. Depression is a common mental disorder that presents with a depressed mood, a loss of interest or pleasure, decreased energy, fatigue, feelings of guilt, sleep or appetite disturbances and a lack of concentration [15,16].

Earlier studies had suggested [17,18] that high levels of trait anxiety were a significant risk factor for the development (onset, severity and outcome) of depression. These findings and the high comorbidity between anxiety and depression (up to 60%), but especially the fact that anxiety disorders precede depressive disorders [19], led Sandi and Richter-Levin [20] to hypothesize a "neurocognitive model". According to this model, the neurocognitive style of trait anxiety (neurocognitive maladjustments) plays a central role in the pathological development of depression [20]. More recent studies have argued that high trait anxiety is an important vulnerability phenotype for stress-induced depression [21]. Moreover, studies in breast cancer patients report trait anxiety as an important determinant of both depressive symptoms and fatigue [22,23]. Cognitive theory argues that stressful life events activate some stable underlying dysfunctional maladaptive self-schemata of individuals, which, through automatic cognitive processes, lead to the onset or worsening of depression [24–26]. In summary, trait anxiety makes an individual susceptible to depression [25].

From the above, it is clear that nursing staff are particularly vulnerable to developing physical and psychological problems, especially during the COVID-19 pandemic. It is worth noting that at the time of the study, Greece was experiencing the peak of the fourth wave of the pandemic with the prevalence of the Delta variant, which caused particularly high mortality rates. At that time (mid-November to mid-December 2021), approximately six to seven thousand new cases were being recorded daily, 600–700 patients were hospitalized in intensive care units and 80-100 deaths per day were attributed to COVID-19, with an increasing trend that was difficult to address by the national health system [27], which suffers from a severe shortage of nursing staff [28]. Therefore, the aim of the present study was to study the prevalence of anxiety, depression and fatigue and to investigate the possible relationships among them. By selecting and implementing targeted interventions aimed at enhancing key protective factors, the development of adverse physical and mental conditions can be harnessed.

#### **2. Materials and Methods**

#### *2.1. Research Design and Procedure*

This was a descriptive correlation study. Data were collected through self-completed questionnaires that were distributed in person to the participants by the researchers. Participation in the study was voluntary. The questionnaire was anonymous, participants had the right to voluntarily withdraw from the study and were aware of the objectives and procedures to be followed.

The study population consisted of a convenience sample of 404 nurses from five large public/academic hospitals in Athens. The above hospitals treated patients with and without COVID-19. The demographics of the study participants included gender and age. Professional information included years of work experience. In the invitation to nurses to participate in the study, an effort was made to make the study sample representative of Greek nurses in terms of gender, years of work and age. The Ethics Committee of the University of Peloponnese approved the study protocol (18699/11-10-2021), as did the Clinical Research Committees of the five hospitals. The study was conducted from mid-November to mid-December 2021.
