Problems with occupational health have been related to biotechnologies, information and automation technologies, chemical substances and physical energy, along with the peculiarities inherent to the aging of the working population, making groups vulnerable to occupational diseases of various origins [1]. The relationship between the work process and life style has been considered a cause of stress and health problems, leading to organic and psychological imbalances and compromising the development of one’s labor activities [2].

Workers in the health field are particularly exposed to continuous stress, which causes physical, psychological and cognitive symptoms, demanding prolonged adaptive responses to tolerate, overcome or adapt to stressors [3]. However, healthcare professionals have been more concerned with improving their activities and the care offered to patients than caring for their own health, especially regarding to occupational risks and mental health [4].

Nursing is associated with high levels of stress, a low degree of quality of life and burnout syndrome [5], due mainly to the long hours and professional dissatisfaction [6]. Moreover, symptoms of anxiety, depression, psychological suffering, sleep disorders, fatigue and other somatic complaints are reported to be associated with the work process of the nursing staff and exert a negative impact on the mental health of these healthcare workers [7].

The workplace and work process should be monitored continually, since there is an association between occupational diseases and the execution of specific nursing procedures, which causes a high level of tension in the work process and reduction in nurses' productivity and life quality [8]. Therefore, an environment that promotes the work process’ organization as well as adequate relationships and communication among staff members, can contribute to the mental health of these workers [9].

The present review’s goal was to identify factors associated with the work process of the nursing staff that exerts a negative impact on these healthcare professionals’ mental health. Thus, the following research question was designed: What factors associated with the work process of the nursing staff exert a negative impact on the mental health of these healthcare professionals?

An integrative review of scientific production was performed. Searches for articles were performed in the Scopus, MEDLINE (Medical Literature Analysis and Retrieval System Online), CINAHL (Cumulative Index to Nursing and Allied Health Literature) and PubMed databases using the MeSh Terms “mental health” and “occupational health nursing”. A total of 783 papers were retrieved, 18 of which were selected for the final sample.

The searches, selection and analysis of the articles were performed by two independent researchers, who compared their findings. In cases of disagreement, a third researcher was consulted and a consensus was reached. The calibration was performed based on the simple means of the correct selection of studies, obtaining 89% agreement during the first calibration exercise and 100% during the second.

For the article’s selection, the titles and abstracts were first read and the following inclusion criteria were considered: studies involving primary data; studies with nursing staff members as the subjects, independently of age, sex, duration of the profession, service or work sector; articles addressing the mental health/illness process and/or substance use by nursing staff; papers published in Portuguese, English or Spanish; articles indexed in at least one of the databases searched. The exclusion criteria were case studies, theses, dissertations, work presented at conferences and review articles. The Fig. (1) shows the flowchart of the study selection process.

Data were extracted from the articles using a validated instrument [11]. The results were presented in tables and text to facilitate the analysis and summarize the scientific evidence, thereby meeting the present review’s objective.

The final sample comprised of 18 studies: five retrieved from SCOPUS, eight retrieved from PubMed and five retrieved from CINAHL. The four articles retrieved from MEDLINE were not included, as these studies were duplicates of those retrieved from the SCOPUS database. Among the articles selected, seven were published in periodicals specific to occupational health. Regarding the design, two were randomized controlled clinical trials, one was a quasi-experimental study, 13 were exploratory descriptive cross-sectional studies with a quantitative approach and two had a qualitative approach. All studies used an instrument to measure the variables of interest. Tables 1-3 display the main findings of the studies.

The articles addressed mental health related to the work process of the nursing staff or nurses alone as the primary or secondary outcome. When mental health was the object of the study, it was considered the primary outcome; when the aspects analyzed led to associations with mental health, it was considered the secondary outcome.

Fig. (1). Database searches’ results of article’s selection by independent researchers and comparison of selections for final sample’s determination based on PRISMA Search Strategy Diagram [10].

The main factors associated with the work process of the nursing staff that exert a negative impact on the mental health of these healthcare professionals were work demands [12-14], aggression [15], violence [16, 17], work accidents involving the risk of exposure to HIV [18], stress [14, 19] and errors in the execution of labor activities [20]. The main mental health findings as the primary outcome of the investigation were post-traumatic stress disorder [15], depression and/or stress [19-23], major depressive episode and/or generalized anxiety disorder [24] and minor psychological disorder [25]. All articles also addressed psychosomatic symptoms of the nursing staff due to occupational risks and factors associated with the work process.

The strategies employed for mental health care of the nursing staff were all group-oriented, such as workshops for training emotional intelligence [26], meetings with an active methodology, followed by individual counseling [27] and a psycho-education group for training communication skills [28]. Despite not addressing mental health as the primary focus, these strategies were able to improve the mental health of the nursing staff and the work process. One article demonstrated that healthy nutrition improved mental health, the work process, job and life satisfaction, as it represented an important aspect of self-care [29].

Based on the findings, the work process of the nursing staff was identified as a source of stress and psychological suffering with physical, mental, individual and collective repercussions. Thus, the work process exposes nurses to occupational risks involving psychological, personal safety, biology and social aspects, all of which are related to mental health.

Nursing staff members are involved in different aspects of health care in which the traditional care model predominates, giving priority to work demands in detriment of the subjective nurses and patients’ needs [30]. The nursing care process is often centered in the individual’s body and health protection, with no ties to the social, historical, cultural, economic and singular aspects of the subject receiving the care. Care also occurs in the form of the knowledge transmission and information aimed at changing the patients’ behavior. This understanding of the nursing work process distanced nursing staff members from concerns regarding their own health and their role as subjects that also require care [31].

The relationship a healthcare professional establishes with oneself and the process of knowing oneself influences the way by which one perceives oneself as a subject that also needs care, thereby affecting the development of actions directed at self-care [32]. Nurses in open sectors generally deal directly with the public and therefore experience higher levels of stress in comparison to those who work in closed units [33]. Factors associated with stress include the patients’ impatience, irritated accompaniers, intolerant physicians, child and emergency care in two sectors at the same time [34]. Moreover, the excessive hourly work load hinders having a social life and enjoying recreational activities, thereby contributing to the physical and mental burden of nursing staff members and exerting a negative impact on both life quality and work performance [33].

Psychological suffering among nursing staff members has been related to the characteristics of the labor organization, work process and patient’s specificity. Factors associated with psychological suffering include little autonomy in the decision-making process, little recognition of the importance of their work, inadequate continued training program as well as a lack of material and human resources [2]. Moreover, exposure to physical and verbal aggression, a lack of job security and low pay contribute to problems such as stress, cardiovascular alterations and sleep disorders [35]. Thus, nurses experience different violence forms of a physical and psychological nature that negatively affect their work performance and health [36].

The demands of the work process of the nursing staff require specialization, technical-scientific knowledge, leadership skills, discernment, responsibility and clinical practice, which places considerable pressure on these healthcare professionals [37]. Moreover, bureaucratic activities, the constant contact with death and human suffering, difficult family relations, the lack of recognition on the part of supervisors and administrators, the lack of encouragement for continued education and the lack of institutional strategies to minimize the physiological and psychological consequences to nurses, patients and family are risk factors for mental illness among of the nursing staff members [37].

Mental illness stemming from stress in the workplace depends on individual aspects and one’s relationship with this environment [38, 39]. The physical symptoms involved in mental illness and a reduction in productivity include musculoskeletal disorders, which are generally associated with chronic pain and disability [40], tachycardia, insomnia, insecurity, anxiety, weariness [41], headache, sensation of fatigue and pain in the lower limbs [34]. Exposure to continuous stress leads the organism to exhaustion and contributes to the emergence of opportunistic diseases; thus, physical stress leads to psychological stress and vice versa [34]. Factors associated with the nursing staff’s work include physical and emotional aspects, and pain, with repercussions regarding work performance and life quality [3]. Thus, knowledge on work-related factors that affect the mental health of nursing staff members is indispensable, as the quality of health care depends on healthy, motivated staff members.

Moreover, care quality and staff members productivity of staff members under stress or with occupational diseases are compromised, leading to high rates of absenteeism and being on leave from work due to health reasons [42].

The working conditions and health of the nursing staff underscore the need for changes in the organization and work process, as well as the responsibility of occupational nurses to develop strategies aimed at factors associated with the work process of this team that affects their mental health [43]. Thus, there is an important relationship between occupational risks and the complexity level of symptoms and diseases stemming from the work process of the nursing staff as the kind of the work environment and the way these healthcare professionals react to the interaction of all these factors [44]. Furthermore, consumption of psychoactive substances causes ill adaptation to the stressor with dysfunction in social and work activities [45].

The theories’ choice to guide nursing practices provides scientific support to the care focus and the evaluation of interventions [46]. Interpersonal approaches include psychoeducation about the patient's role, formulation of the problems from an interpersonal perspective, exploration of options for changing dysfunctional behavior pattern [45]. Considering the findings of the present study, we suppose that high level of perceived job satisfaction could be related to the “community centered model” in mental health care services. Similar studies should be conducted by including different types of mental health organizations, such as psychiatric hospitals, to explore the differences [47].

The planning of interventions directed at health problems stemming from the work process of the nursing staff requires a diagnostic assessment. According to the organic law of Health n. 8080/90 of 19 September 1990 [48], an action that aimed the mental’s health prevention and the promotion of occupational health should be part of any healthcare program directed at the nursing staff.

Thus, strategies for protecting the nursing staff’s health should address three health care levels: basic (prevention of occupational risks and mental health promotion), moderate complexity (direct care of the problem) and high complexity (follow up and assistance to return to the workforce).

The scientific evidences on the mental health and work process of the nursing staff were identified: mental health risk factors, the relationship between mental illness and both physical symptoms and productivity related to work activities as well as feeling and perceptions of the nursing staff members regarding the work process and their mental health. The risk factors identified were work-related accidents, violence in the workplace, the physical and mental demands of the job, excessive work activities, work pressure, poor relationships with the nursing team and administrators and individual psychological characteristics.

The findings demonstrate that mental illness causes physical symptoms and lowers productivity, with repercussions to the nurses’ lives of nurses and their family/social relations. Thus, mental health, occupational health and the work process are interrelated and can influence one another in a positive or negative fashion. The strategies identified to preserve the nursing’s staff mental health include the training of communication skills, emotional intelligence and participative management.

This study provides a better understanding of the nursing staff’s mental health complexity, demonstrating that the work process of these healthcare professionals involves peculiarities that expose nurses to the risk of physical and mental disorders. This study also highlights the importance of occupational nurses and their work regarding the health care of their work teams.

The nurse’s work need to understand the problems’ complexities of mental health and substance use among nursing workers to recognize, identify and take care of workers at risk, providing adequate mental health care. Although this theme has gained increasing interest from researchers, proving that all these factors contribute to the risk to mental health of nursing professionals, the protective measures and care are being neglected by managers in both the private network, the public network. The health of nursing workers is another challenge for this profession that needs to be taken care of and should be careful.