Suicidal ideations among students attending vocational school in Germany: a cross-sectional study to identify prevalence and associated risk factors

Even though students attending vocational school are very vulnerable to the development of mental health problems, few studies identify the correlation between suicidal ideations and vocational education. Therefore, this study aimed to identify the prevalence and associated risk factors for suicidal ideations among vocational students in Germany. We conducted a cross sectional survey with a total of 555 pupils. The pupils received a standardized questionnaire, assessing sociodemographic data, the use of protective factors, possible risk factors, traits for neuroticism and depressive symptoms. For our study, we excluded item 9 from the Beck depression index (BDI-II) to identify the prevalence of suicidal ideation. Our results show that the prevalence of suicidal ideation among students attending vocational school is 23.2%. A combination of feeling lonely, male sex, low importance of religion, little time for hobbies and BMI scores outside the norm show the highest risk for suicidal ideation and can be identified as significant predictors. This cross-sectional study highlights the mental burden vocational students in Germany are confronted with and underlines the necessity of paying special attention to this group of young adults. Furthermore, it emphasizes the necessity of further studies on this topic, especially including larger student populations. The results should be used to decrease the significant loss of life caused by suicidal behavior in young adults.


Introduction
Suicide has become a significant global health problem.
According to the WHO (2019), almost 700,000 deaths by suicide are recorded per year.It is becoming one of the leading causes of deaths worldwide.Alarmingly, it is also the second leading cause of death for young adults aged 15 to 29 years old (WHO 2019).
In Germany for example, approximately 10,000 people per year are affected by suicide, 900 of these being under the age of 30 (FBS 2020b).
Suicide ideation is one of the major predictors for committing or attempting suicide (Nock et al. 2008).It can be used as a reliable indicator for measuring suicidal behavior.Suicide ideation is defined as "thoughts of engaging in suicide behavior intended to end one's life" (Nock et al. 2008).Globally, the numbers for suicide ideation vary.According to Weissman et al. (1999) the lifetime prevalence rates per 100 people for suicide ideation range from 2.09 in Beirut to 18.51 in New Zealand.In Germany, suicidal ideation was reported by 8.0% (Forkmann et al. 2012).Worryingly, the numbers for suicide ideation among young adults are even higher: Studies show that 24% of adolescents in America considered ending their lives in the past year.(Becker et al. 2004;Van Heeringen 2001) Several risk factors can be associated with suicidal ideation: These vary from sociodemographic components such as gender, age, ethnicity, social status or occupation to genetic traits or personality characteristics (Bridge et al. 2006) In addition, proximal risk factors such as psychiatric disorders seem to play a major role.Ultimately, alcohol or substance abuse, especially dependence, is strongly associated with suicide risk (Conner and Duberstein 2004).Moreover, psychological factors such as hopelessness (Beck et al. 1985), loneliness (Van Orden et al. 2010) and high emotional reactivity (Fawcett 2001) have been proven to be strongly correlated to suicidality.
In Addition to the above-mentioned risk factors, stressful life events seem to be the trigger for an actual suicide attempt.These include family and relationship conflicts, financial and legal problems, or the presence of persistent stress (Brent et al. 1993).
According to the Federal Bureau of Statistics (2020a) about 12.3 million pupils in Germany have attended vocational school in 2019.Approximately 30% of these pupils were not satisfied with their education: They complained about working extra shifts, having financial difficulties, not getting enough free time for social activities and too little time to prepare for exams.Many felt extremely stressed and work overloaded (DGB 2018).This makes them vulnerable for developing mental health problems.Considering the above-mentioned risk factors associated with suicidal ideation, the question arises whether attending vocational school can be identified as a possible risk factor for suicidal ideation.
Unfortunately, there are only very few studies that examine the correlation between suicide ideation and vocational education (Benatov et al. 2016;Dalen 2012;Silviken and Kvernmo 2007;Tandon et al. 2008;Tsai et al. 2011).Dalen (2012) identified that suicidal ideation is higher in classes following a vocational education program.Silviken and Kvernmo (2007) also identified that young adults attending vocational education had an increased risk in reporting suicide attempts.Contractionary, Tandon et al. (2008) on the other hand reported that suicide rates among young adults in Baltimore, USA, attending vocational education were less than in students not attending vocational education.
This observation was also made by Benatov et al. (2016), stating that the overall rate for suicide ideation and attempts among vocational education students were lower compared to students in the regular educational system.There have not been any comparable studies on this topic in Germany.
After a thorough examination of the topic and its corresponding literature, it became clear that the studies done showed very inconsistent results.Some identified that students attending vocational education posed a higher risk for suicidal ideation, others stated the contrary.In Germany, studies on this topic were nonexistent, demonstrating it is a topic that receives very little attention.With these gaps in research in mind, we examined students from a vocational school in Germany with the aim to: (a) identify the prevalence of suicide ideation among vocational students in Germany and (b) to identify possible risk factors correlated to suicide ideation among vocational students.

Methods
This study is part of a larger project on mental health in students of medicine, dentistry, law, and psychology.The primary aim of this project was to assess the prevalence of depressive symptoms in these student groups and to identify associated risk and resilience factors.

Design and data collection
The following data was collected from students attending vocational school for health, personal care, and social education in Halle/Saale.It is one of the largest vocational schools in the federal district of Saxony Anhalt with about 1550 pupils.The vocational education system in Germany is a training program for non-academic professions.It is divided into alternating terms of school education and practical trainings.
The study took place from November 2019 until January 2020.For this study, a cross sectional questionnaire survey was implemented.The questionnaire was handed out during compulsory seminars in the middle of the academic year.We invited pupils from first to third year of different trainee groups including physiotherapists, medical/dental assistants, child and elderly care professionals, health care professionals, hair stylists, dental technicians, beauticians, curative education nurses, social care professionals, educators, and landscape and gardening technicians.
Participation was voluntary.For legal reasons, we only interviewed pupils over the age of 18.The pupils were asked to pseudonymize their questionnaires with a code to allow longitudinal follow up.Before filling in the questionnaire, participants were informed about the primary aims of this study.

Participants
All pupils over the age of 18 years who were currently attending vocational school and not completing their practicals (N = 789) were eligible to participate in the study.
Out of those, n = 702 were available and asked to participate.However, 10.1% (n = 71) were under the age of 18 and therefore could not participate.The response rate of the remaining n = 631 was 88.0%.Thus, the total sample size included 555 participants.
Of these participants, 27.8% (n = 154) were in the first year, 50.4% (n = 279) in the second year, and 21.8% (n = 122) in the third year.The age of the total sample ranged from 18 to 56 with a mean of 22.3 years (SD = 6.4).Most of the pupils (83.7%) were 18-25 years old, 10.4% had an age range from 26-35 years, 4.2% from 36-45, and 1.5% had an age above 45 years.The majority was biologically female (78.0%), 21.8% were male, 0.2% did not respond to this question.

Dependent variable-suicidal ideation
For assessment of suicidal ideation, the respective item from the Beck depression index (BDI-II) was used as the primary dependent variable (Beck et al. 1996).The BDI-II consists of 21 items and is a reliable and valid assay method to record the severity of depressive symptoms among young adults (Lee et al. 2017).Item 9 poses the question whether the subject has had suicidal thoughts within the last two weeks before the survey.
The following options were available: 0= "I don't have any thoughts of killing myself."1= "I have thoughts of killing myself, but I would not carry them out."2= "I would like to kill myself."3= "I would kill myself if I had the chance."Since answers stating higher scores than "1" were rare, we converted this item into 0/1 (suicidal ideations vs no suicidal ideations).

Independent variables -risk and resilience factors
Apart from sociodemographic factors such as age and gender, our standardized, self-designed questionnaire accessed potential correlating risk and resilience factors that were previously associated with suicidal behavior.These included lifestyle factors, social life factors, mental health factors, and factors associated with vocational studies.They are described in more detail below.Further details on variable scaling have been published by Kindt et al. (2021) and Pukas et al. (2022).

Lifestyle factors
Lifestyle factors included questions concerning regular meals, BMI and a healthy diet.Regarding hobbies, participants were asked whether they played an instrument for one hour or more or if they did sports for at least two hours per week.They were also asked if they were satisfied with the time they had for hobbies.
Other lifestyle factors participants were asked about were numbers of days consuming alcohol, number of smoked cigarettes, using food to calm down, using meds/ drugs to calm down, using meds/drugs to enhance focus.

Social life factors
Social life factors included living alone, feeling lonely, relationship longer than 3 months, happiness with relationship, having children, happiness with family, happiness with friendships, sufficient emotional support, sufficient financial funds, and importance of religion.

Mental health factors
Regarding mental health, participants were asked for "positive family history of mental disorders" that was given if at least one first or second-degree relative (siblings or [grand-]parent) was under treatment for at least one mental disorder other than dementia.Furthermore, they were asked about prior own mental health issues, symptoms of fear, psychosomatic symptoms, and confiding own worries to no one.
The adjusted BDI-II score, which is a widely used questionnaire in both clinical and non-clinical samples of adults and adolescents, was used to assess depressive symptoms (Beck et al. 1996).The BDI-II covers 21 multiple-choice items that can each be rated on a 4-point Likert-type scale ranging from zero to three.For this study we summed up all single items scores except item 9 (since this was our primary dependent variable).Thus, the total score in this study could range between 0 to 60 points.
Since neuroticism is strongly associated with the development of depressive symptoms and suicidal ideation (Bonsaksen et al. 2018), participating students also completed the neuroticism subscale of the NEO-FFI.According to norms presented by Borkenau and Ostendorf (1989), the NEO-FFI scale score of 2.54 represents one SD above population mean.We used the scale score as a continuous variable in correlation analyses.Additionally, we present the proportion of students with scores above this cut-off as determination for the prevalence of neuroticism as a risk factor.

Factors associated with vocational studies
Factors associated with vocational studies included: Uncertainty to graduate school, prior vocational training, happy with studies, competition between classmates, learning difficulties, mental overload, performance pressure, hours spent with part time job, and insufficient time for studies.

Data analysis
The statistical analysis was carried out using the software IBM Statistical Package for Social Sciences (SPSS 20.0).The evaluation of the frequency of suicidal ideation was done by descriptive statistics and the determination of relative frequencies of the BDI-II item 9.
For evaluation of associations between suicidal ideation (dichotomized) and factors of lifestyle, social life, vocational studies and mental health, either phi coefficient (for dichotome variables) or Spearman rank correlation (for ordinal scaled variables) was calculated.
Since adjusted BDI-II total score was skewed and significantly deviated from normal distribution (Kolmogoroff Smirnoff-Z = .137;p < 0.001), also Spearman rank correlation was calculated.
To determine the influence of the risk factors on suicidal ideations that proofed to be correlated and to control for intercorrelation (multicollinearity), linear multiple regression was used (stepwise, p in = .05;p out = .10).

Prevalence
Results show that N = 129 students (23.2% of the total sample) stated suicidal ideation within the past two weeks.Most of them (89.9%)used the mildest statement "I have thoughts of killing myself, but I would not carry them out," n = 13 students used more advanced options.The total prevalence of suicidal ideation was slightly lower in last year pupils (17.4%) compared to first year students (27.8%) or second year students (24.7%), but missed statistical significance (Χ 2 [df=2]=3.07;p = 0.216).

Univariate results
To evaluate associations between risk factors that have been discussed in previous research, univariate correlation coefficients between suicidality (dichotomized) and each risk factor were calculated.Results are shown in Table 1.
Results show that there were no correlations found regarding sociodemographic factors or lifestyle factors.Also, factors associated with vocational studies showed no significant correlation to suicidal ideation.Nonetheless, hours spent with a part time job showed negative correlations.
Conversely, alcohol consumption showed negative correlations to suicidal ideation.
When looking at social life, low subjective importance of religion and living alone were associated with suicidal ideation.
The highest correlation to suicidal ideation where found in the category mental health, including adjusted BDI scores ( r = .439) and neuroticism ( r =. 378 ).

Multivariate results
In order to control for intercorrelation (multicollinearity) between the significantly correlated variables, we conducted a multivariate linear regression model (stepwise, p in = .05;p out = .10).Results of the final model are shown in Table 2.The results show that significant predictors were adjusted BDI-scores above all and additionally the following items: feeling lonely, male sex, low importance of religion, little time for hobbies, and BMI scores outside the norm.
VIF of the included predictors was always below 1.03.Therefore, multicollinearity between these variables was neglectable.

Discussion
Considering that only few studies have investigated suicidal ideations in vocational education, the aim of this study was to systematically evaluate the prevalence of suicidal ideation among a large sample of vocational students in Germany and to identify possible correlating risk factors in this sample.

Prevalence
Our results show that the prevalence of suicidal ideation among students attending vocational school within the past two weeks is 23.2%, indicating that almost every fourth student has had thoughts of killing themselves in the past two weeks.This is an alarmingly high number, considering that suicide is the second leading cause of death for young adults aged 15 to 29 years old (WHO 2019).
Comparing our data to other studies, the prevalence found in our study coincides with the few existing data from other vocation student populations, ranging from 16% among vocational education in Israel (Benatov et al. 2016) to 28% among vocational students in Norway (Dalen 2012).Nonetheless, these studies used different screening tools and a different time span in which suicidal ideation occurred and are therefore not ideal for comparison.This emphasizes the importance of standardized survey methods for mental health studies.Other studies did not directly evaluate the prevalence of suicidal ideation among vocational students, but identified vocational education as a main risk factor (Silviken and Kvernmo 2007).Comparing our prevalence rate with other student populations in Germany, for example, medical university students (Rotenstein et al. 2016) with prevalence rates between 11 and 12% or law university students with a prevalence rate of 17.7% (Rabkow et al. 2020), our study shows higher prevalence rates for suicidal ideation in vocational education.This suggests that in vocational education, suicidal ideations are more frequent than in university students of similar age and even in similar geographic regions.

Risk factors and protective factors
The second aim of this study was to identify risk factors correlated to suicidal ideation in our study population.Early identification of these factors is crucial in order to offer appropriate support and treatment and prevent deaths by suicide.As expected from other studies (Ang and Huan 2006;Brent et al. 1993;De Man 1999), the BDI-Score had the highest correlation to suicidal ideation and predicted it reliably.Another risk factor that showed high correlation to suicidal ideation in our study population was neuroticism.This coincides with previous studies made on this topic (Rappaport et al. 2017), including a meta-analysis by García Herrero et al. (2018), identifying neuroticism as a main risk factor for suicidal ideation.Nonetheless, it is important to keep in mind that current depressive symptoms can affect the outcome of self-assessed neuroticism tests (Gámez et al. 2007;Griens et al. 2002).
Last, the risk factor "living alone" showed significant correlations to suicidal ideation among students attending vocational school, matching the results found in previous studies (Calati et al. 2019).
Contrary to several findings (Conner and Duberstein 2004;Curran et al. 2009), alcohol consumption was not identified as a risk factor but instead showed negative correlations to suicidal ideation.This could be explained by the fact that young adults mostly consume alcohol with friends or in groups, resulting in a positive effect on their social life.Furthermore, hours per week spend with a side job also showed negative correlations for suicidal ideation.
In a further step we identified the most important factors by using a regression model.Our results show that a combination of feeling lonely, male sex, low importance of religion, little time for hobbies, and BMI scores outside the norm show the highest risk for suicidal ideation and can be identified as significant predictors.The vocational system must therefore be highly alert to students indicating these factors since they may pose a greater risk to develop suicidal ideation and attempt.

Limitations
There are several limitations that must be considered when interpreting this study.
Our study included a large sample size of n = 550 students attending vocational school and showed a high responsive rate of 88%.Nonetheless we only asked students from one middle sized vocational school in Germany, limiting the studies ability to generalize results to the entire vocational school population.Therefore, further studies are needed on this topic.Ideally, these should include a larger number of vocational colleges in Germany in order to make the results more generalizable and to identify whether the high prevalence rates conducted in our study are a German/worldwide problem.Furthermore, we only questioned pupils who were attending vocational class and not students who were doing their practical part of vocational training, missing out on potential risk factors.
Since our study was a cross-sectional study, the direct causality could not be identified.Therefore, longitudinal studies that observe the suicide risk of vocational students throughout their education would be recommendable.
Since the study was primarily designed to survey depressive symptoms, we did miss important risk factors with high impact on suicidal behavior.These include previous suicide attempts or suicide attempts in family and friends.Other risk factors such as genetic traits or social media behavior were also not monitored.
Regarding our method, the BDI-II score, one should have in mind that a self-report instrument can be easily influenced by a diversity of factors, for example, crowded classrooms, chitchatting, or sitting next to friends.The respondents may overreport (Carter et al. 2010) or underreport (Hunt et al. 2003) on their symptoms, so the results can be falsified and should be treated with caution.We therefore handed out the questionnaires anonymously, preventing false positive results (Levine et al. 2003).Nonetheless, while it may not replace an objective clinical examination, it can be seen as a reliable tool to estimate the prevalence of suicidal ideation among vocation students.

Conclusion
This cross-sectional study on the prevalence of suicidal ideation among German students attending vocational education shows that nearly every fourth student attending vocational education has had thoughts of killing themselves in the previous two weeks.This alarmingly high prevalence rate highlights the mental burden vocational students are confronted with and underlines the necessity of paying special attention to this group of young adults.
Furthermore, this study emphasizes the necessity of further studies on this topic, examinating potential risk and protective factors and incorporating larger student populations.New studies should include recent advances in survey methods on mental health and results should be used to decrease the significant loss of life caused by suicidal behavior in young adults.
Authors contributions All authors contributed to the study conception and design.Material preparation, data collection, and analysis were performed by Patricia Lamle, Heiko Röder, Juliane Reinsch, and Hanna Clausner.The first draft of the manuscript was written by Patricia Lamle and all authors commented on previous versions of the manuscript.All authors read and approved the final manuscript.Supervision was performed by Stefan Watzke.
Funding Open Access funding enabled and organized by Projekt DEAL.This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Data availability
The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

Table 2
Multivariate linear regression model for prediction of sui-