Psychological distress in nursing students: relationship with screen time, diet and physical activity

Objective: to determine the prevalence of anxiety and depression symptoms, as well as their association with screen time, diet and physical activity, in a cohort comprised by nursing students. Method: a descriptive and cross-sectional study conducted with a sample of 648 Nursing students. The instruments used were the Hospital Anxiety and Depression Scale, the short version of the International Physical Activity Questionnaire and the Spanish Healthy Eating Index (Índice de Alimentación Saludable Español, IASE). Different multiple linear regression models were performed to analyze the association between anxiety/depression symptoms and screen time, diet and physical activity. Results: the prevalence values for anxiety and depression symptoms were 24.1% and 3.7%, respectively. Prolonged screen times (>6 hours a day), low levels of physical activity and inadequate diet were independently and significantly associated with deeper psychological symptoms. Conclusion: Nursing students’ mental health might benefit from the implementation of initiatives promoting healthy lifestyles.


Introduction
Mental health problems are one of the leading causes of disability and an increasing public health issue at the global level due to disease progressions, their increased prevalence and the difficulties associated with their therapeutic management (1) . On many occasions, mental health problems appear in early adulthood and, in this life phase, they are associated with higher incidence of medium-and long-term physical and emotional problems (2) , with difficulties entering the labor market (3) , with worse sleep quality (4) or with dysfunctional social relationships (5) , among others.
University students are faced with important challenges, risks and transitions inherent to social development that increase the risk of suffering mental health problems (6) . In addition, the stressors can be even greater in the case of future nurses. Clinical practices imply close human contact based on deep emotional commitment, and may include dealing with severe diseases and deaths (7) .
Previous studies have characterized psychological distress by assessing depression and anxiety in nursing students at the global level, reporting high results, although significantly dissimilar (8)(9)(10) . From this perspective, it is of special importance to monitor and early detect psychological distress in nursing students, as well as its associated factors. In this sense, both in the clinical population and among adolescents and young individuals, several research studies have observed certain associations between specific behaviors and anxiety/ stress. Among them, inadequate diet (11)(12) and sedentary lifestyle with considerable time devoted to using devices with a screen (13)(14) seem to be associated with greater psychological distress. On the other hand, physical activity seems to exert a protective mechanism against anxiety and depression. However, these relationships are yet to be confirmed in specific populations such as university students and, more in particular, nursing students.
Based on these deficits, the objective of this study was to characterize psychological distress in local nursing students, based on determining the prevalence of anxiety and depression symptoms, as well as their association with screen time, physical activity and quality of the diet.

Method Study design and locus
A descriptive and cross-sectional study was conducted with a sample comprised by nursing students enrolled in any of the two institutions that offer this degree in the Aragon Region (Spain), namely: Universidad de Zaragoza and Universidad San Jorge.

Population
Calculation of the minimum sample size required to meet our main objective of determining the prevalence of anxiety and depression was based on results recently obtained through the Hospital Anxiety and Depression Scale (HADS) in a sample of Nursing students from the Principality of Asturias (Northern Spain) (15) . Consequently, for a 95% confidence level and 2% absolute precision, a required minimum of 610 participants was estimated for our study.
Recruitment of the participants and data collection were conducted in the classrooms from September to November 2022. Thus, the students were informed about the study nature and objectives, the voluntary character of their participation and about how the data obtained would be managed based on the anonymity criterion.
From an eligible enrolled population of 1,182 students, 682 consented to take part in this study and answered the required questionnaires (response rate: 57.6%). Of all 682 questionnaires received, 34 were considered as not valid (generalized absence of data or overtly unreal data) and were consequently excluded from the analysis (rejection rate: 5.0%).

Variables and instruments used for data collection
The data collection questionnaire had three sections:  The participants' eating habits were assessed with the Spanish Healthy Eating Index (Índice de Alimentación Saludable Español, IASE) (18) . This tool is an adaptation of the Healthy Eating Index (19)  Although it has not yet been validated for the Spanish university population, the original Healthy Eating Index questionnaire has indeed been validated through plasma biomarkers, showing satisfactory correlation levels ranging from a minimum of r=0.23 (for cereals) to a maximum of r=0.71 for food variety (22) . were considered for the participants with scores ≥8, whereas probable depression and probable anxiety for those with values ≥11 in the respective subscales (24) .
In its validation study on the Spanish population, this questionnaire has shown optimum properties for anxiety and depression screening (25)(26) .

Data analysis
The descriptive analysis corresponding to the characteristics of the sample (sociodemographic, academic, lifestyle-related, and psychological symptomatology) is presented through mean values and standard deviations for the quantitative variables, and with numbers and percentages for the categorical ones. The bivariate comparison of those characteristics based on gender was performed through the Student's t test for the quantitative variables using the χ 2 test (or Fisher's Exact test when applicable) for the categorical ones.
In addition, several multiple linear regression models were performed with the objective of determining the association degree between screen time, physical activity, diet and anxiety/depression symptoms, both for the total population and by sex. The models performed on the total sample were adjusted by age, sex, economic situation, mean grade, academic year, housing arrangement and work situation, as well as by screen time and diet (for

Ethical considerations
Prior to initiating the study, due authorization was obtained from the Aragon Clinical Research Ethics Committee. Initially, the participants were informed about the objectives, methodology and potential risks arising from their participation in the study and about the possibility of withdrawing from the research at any moment. Subsequently, and prior to data collection, all the participants signed the informed consent form.

Characteristics of the sample
A total of 648 nursing students comprised the final study sample. The participants' mean age was 21.7 years old and the female gender prevailed (84.2%).
Most of the participants were enrolled in 2 nd or 3 rd year of the course (50.3%), lived with their parents/family members (60.2%), perceived their economic level as average (85,2%) and had no paid jobs (76.9%). By sex, no statistically significant differences were observed in relation to age, academic year and grade or work situation. However, men were more prone to living alone than women (p<0.05) (

Anxiety and depressive symptoms
The mean scores obtained in the HADS-A and HADS-D  (Table 3). By sex, the scores obtained in HADS indicated greater anxiety and depression traits in women and men, respectively (p<0.05), although the probability of finding severe clinical signs of depression was slightly higher in the women's group.

Association between physical activity, screen time, diet and psychological symptoms
All three multivariate analysis models (for the total and by gender) performed to evaluate the association between physical activity, screen time, diet and the anxiety symptoms showed that low levels of physical activity, prolonged screen times (>6 hours) and unhealthy diets (diet requiring changes and inadequate diet) are statistically and significantly associated with higher scores in the HADS-A anxiety scale. These behaviors are maintained both for the general sample and in the analysis disaggregated by gender. The predictive capacity of these three models ranged between 19.5% and 67.4% (Table 4). associated with higher scores in the HADS-D scale. The behavior of these associations was similar in men and in women. However, an inverse association between physical activity and depression was only observed in the men's group. Thus, the higher the physical activity level, the fewer the depressive symptoms (lower HADS-D scores) in men. The predictive capacity of these models ranged between 20% and 78% (Table 5).

Discussion
The objective of this research was to examine the prevalence of anxiety and depression in a sample comprised by Spanish nursing students, as well as their association with screen time, physical activity and quality of the diet. We were able to detect high prevalence of risk behaviors for health, such as low levels of physical activity (51.9%), deficient diet (40.7%) and prolonged screen times (13.9%) among local future nurses. These values are similar to those already obtained in samples comprised by Spanish university students (27)(28) . They are high prevalence values for unhealthy lifestyles, which deserves double consideration in the case of nursing students.
On the one hand, unhealthy habits predict mediumand long-term health problems for these young people.
On the other hand, the nursing staff is a reference in relation to health education and the promotion of healthy lifestyles. In this sense, the already published literature suggests that the health professionals' behaviors exert an influence on their health promotion practices (29) . It is worth noting that these behaviors were associated with psychological distress. Thus, high levels of physical activity were inversely associated with presence of anxiety and depression symptoms. This relationship has already been reported in various populations (30) and may be sustained from a neurobiological point of view due to the activating effect of physical activity on the endocannabinoid system and the brain-derived neurotrophic factor (31) .
Previous research studies have evidenced significant associations between healthy eating habits (moderate calorie intake, having breakfast or not eating snacks, among others) or intake of certain food products and nutrients (vegetables and fruit, polyunsaturated fatty acids, certain minerals or vitamins, among others) and good psychological health (32)(33) . In this same line, the quality of our participants' diet was inversely and strongly associated with presence of anxiety and depression.  (34)(35) .
of depression and anxiety symptoms in university students, respectively (36) . Comparing these values with those obtained in cross-sectional studies, such as in this case, is a difficult task given the heterogeneity of socioeconomic contexts and the variety of diagnostic instruments used. In any case, they are higher numbers than those observed in our sample of nursing students, where approximately one-fourth of the participants presented some type of psychological distress, with higher prevalence of anxiety (24.1%) than of depression (3.7%) symptoms. These results seem to be contrary to the theory which asserts that students from the health area present higher psychological distress levels than others for being subjected to more stressors, including contact with diseases and deaths (37) .
Several studies have already analyzed the prevalence of psychological distress in nursing students, with very heterogeneous results according to the participants' countries of origin. For example, in Canada, depression and anxiety symptoms have been observed in 32% and 39% of the students, respectively (38) . These values differ from those obtained in Turkey (depression symptoms in 55.5% and anxiety symptoms in 50.9%) (39) , Brazil (depression symptoms in 54.2% and anxiety symptoms in 40.1%) (40) , Japan (depression symptoms in 18.3% and anxiety symptoms in 34.6%) (41)  However, they are not specific to any given academic discipline or based on scientific evidence. In this sense, some authors suggest certain strategies capable of minimizing psychological distress, such as behavioral interventions (43) , mindfulness (44) or mentoring programs (45) .
In addition, nursing students subjected to stressful situations in their care practice internships might be benefited if simulation scenarios were incorporated into the curriculum. These spaces may help nursing students to gain confidence, anticipate situations and develop effective coping strategies for their future performance in emotionally complex situations (46) .

Conclusion
The results of this study show considerable prevalence of depression and anxiety symptoms in Spanish nursing students. In addition, these symptoms are associated with low levels of physical activity, prolonged screen times and unhealthy diets. These data suggest two important problems towards the future. The first one refers to the future nurses' medium-and long-term health. The second one concerns their future performance as nursing professionals, which can be impaired by lower promotion of their patients' health (a person cannot so vehemently promote something they do not comply with) and by greater exposure to the burnout phenomenon, which is more incident in professionals with a less favorable baseline psychological status. These predictions denote the importance of implementing strategies that promote general and mental health in the university setting. www.eerp.usp.br/rlae