Mental disorders are a main cause of loss of productivity and global burden of disease [1, 2]. Recently, researchers and policy makers have become interested in suicides and mental disorders related with working conditions such as long working hours or low wages; psychosocial factors such as job strain, unemployment, job instability, or emotional demand; and workplace violence from a third party or supervisor in South Korea [3–6].

In 2013, the Ministry of Employment and Labor (MOEL) in Korea amended the Enforcement Decree of Industrial Accident Compensation Insurance (ED-IACI) Act and added post-traumatic stress disorder (PTSD) due to work-related psychological trauma [7]. In 2016, the MOEL amended the ED-IACI Act again and added depressive episodes or adjustment disorders due to third-party workplace violence or directly related stress [8].

In South Korean, the recognition process for all of the mental disorder including PTSD was same with the process of occupational disease. At first, the Korea Workers’ Compensation and Welfare Service (COMWEL) conducts investigations about the exact diagnosis, working condition, work stress, symptoms and signs, medical records, or individual risks. Finally, Committee on Occupational Disease Judgement (CODJ) composed with occupational physician, psychiatrist, or law expertise decided whether the disease compensated with IACI or not [9].

According to the Epidemiologic Survey of Mental Disorders of the Ministry of Health and Welfare, in 2011, the lifetime prevalence of major mental disorders was 27.6 %, of mood disorder were 3.6 %, and of anxiety disorders was 6.0 % in adults aged 18–74 years [10]. However, the specific situations related with or prevalence of workers’ mental disorders is unknown.

This study aimed to identify the characteristics of and major work-related stressors related with claimed mental disorders, which the workers believed to be caused by work-related stress or a specific event.

The most common claim was suicide (23.0 %, n = 203), followed by depression (14.9 %, n = 132), adjustment disorder (9.6 %, n = 85), and PTSD (7.2 %, n = 64). Other disorders included systemic disorders such as musculoskeletal disorders, heart disorders, or gastrointestinal disorders, which are not mental disorders.

There was an increase in claims due to mental disorders or suicide during the 5-year period. The approval rate was approximately 33 %, and the main stressor was an acute stressful event, including physiologic trauma, employment-related issues, fear of legal or financial responsibility, abrupt change in organizational responsibility, or workplace violence.

Regarding suicide, fear of legal or financial responsibility was a reported work-related stressor; this is also related with economic problems. The second stressor was responsibility related with an ethical problem or qualification; examples include an inspection by the Prime Minister’s Office, sudden progression in actual or acting authority, sudden change in supervisor or task, pressure to solve a socially-focused issue (e.g., environmental disaster), unexpected transfer, or competitive performance evaluation. Another main stressor was interpersonal relationships related with mobbing, bullying, or workplace violence. Finally, employment-related issues such as a transfer without agreement, resignation, notice of discharge, or termination of contract were important causes of suicide or mental disorders.

Managerial and office work were the primary main occupation of the workers with a claim. This is very different from the occupations reported for other occupational disorders or occupational injuries. Blue collar were usually main occupations for occupational injuries or diseases [11]. This could be related with financial or legal responsibility, which is also related with economic problems and labor market characteristic of labor market; for example, 62.3 % of employees are white collar or service workers [12].

Adjustment disorder, acute stress disorder, and PTSD were commonly approved disorders, while approvals were typically not granted for panic disorder or schizophrenia. The first three disorders are caused by external stress or trauma, as classified in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) [13]. In contrast, panic disorder or schizophrenia is considered to be caused by intrinsic factors.

IACI does not compensate for suicide or self-harm, in principle. When the injury, disease, disability, or death is caused by any act committed in the state of a marked decline in his/her normal cognitive function, as prescribed by Presidential Decree, it is deemed an occupational disease [14]. The three exceptional cases include self-harm in a state of mental disorder by a person who received or is receiving medical treatment for a mental illness arising from work-related reasons; by a person who is receiving medical care due to a work-related accident, and the mental disorder is caused by the work-related accident; and by a person due to work-related reasons, when the relationship between the reason and self-harm is medically recognized [14]. Therefore, regarding the approval rate of approximately 36 %, we did not attempt to determine a causal association between stress and suicide or compare the figure with that from other countries. However, considering that there was an increase in claimed cases and the suicide rate among employees was very high in Korea, various epidemiologic study to identify cause, trigger, underline risk factor, or high risk group of suicide, for example case–control study using psychological autopsy, cohort study, or other study using various research methods are also needed.

KCOMWEL provided all documents related to claimed cases. Therefore, the documents may have mainly included the employee’s or their family’s subjective opinion or theirs ideas depending on how much they remember. This suggests that all study subjects want to approve of their claim and the findings of this study may not be representative of the status, occupational stressors, or mental disorders or suicides among all workers. We also analyzed official documents and statements from KCOMWEL and CODJ.

We conducted text review by developing a common form for descriptive analyses but we could not verify the validity and reliability of this form. However, only three occupational physicians conducted the text review and one physician reviewed all data after the first review.

To our knowledge, this is the first descriptive study to investigate the trends and issues related with occupationally claimed mental disorders and suicides among employees. We used qualitative and quantitative methods to identify the main claimed cause of mental disorders and suicides. The findings are few but are important as fundamental data that are be used by future studies.