Journal List > Korean J Occup Environ Med > v.24(4) > 1125602

Kim, Park, Kim, Lim, Lee, Jeon, and Huh: Association between Long Working Hours and Suicidal Ideation



This study was conducted to investigate the relationship between long working hours and suicidal ideation.


Data based on the fourth Korea National Health and Nutrition Health and Nutrition Examination Survey_(2007~2009) pertaining to a total of 4,539 full-time workers were analyzed. Working hours were divided into four groups (<40 hours/week, 40~51 hours/week, 52~60 hours/week, >60 hours/week). The relationship between working hours and suicidal ideation was then analyzed after adjusting for general and occupational characteristics using a multivariate logistic regression model.


Working 40-51 hours/week showed the lowest suicidal ideation(9.5%), whereas working 52~59 hours/week, over 60 hours/week and less than 40 hours/week showed suicidal ideations of 14.8%, 15.7% and 17.2% respectively. Even after adjusting for general and occupational characteristics, employees working 40~51 hours/week had the lowest suicidal ideation. Working 52~59 hour/week, over 60 hours/week and less than 40 hours/week showed an odds ratios of 1.413(p-value: 0.058), 1.380(p-value: 0.020) and 1.164(p-value: 0.358) respectively.


The results suggest that working long hours, especially over 60 hours per week, is related to suicidal ideation.

Figures and Tables

Table 1
Number of workers with suicidal ideation by general characteristics N(%)

*by chi-square test.

Table 2
Number of workers with suicidal ideation by occupational characteristics N(%)

*by chi-square test.

Table 3
Association between working hours and suicidal ideation

*odds ratio by univariate logistic regression analysis.

multivariate logistic regression analysis, adjusted for general characteristics (age, gender, educational status, stress, marital status, depression, household income and sleeping duration).

multivariate logistic regression analysis, adjusted for general and occupational characteristics (age, gender, educational status, stress, marital status, depression, household income, sleeping duration, employment status, working type, occupation and industry type).


1. International Lobour Office Geneva. Decent working time: Balancing worker's needs with business requirements. 2007. International Labour Organization;3–18.
2. National Institute Of Occupational Safety & Health. Overtime and extended work shifts: Recent finding on illnesses, injuries, and health behaviors. cited April 2004. Available:
3. OECD. OECD factbook 2011: Employment and hours worked. 2011. 164–165.
4. Department of mental health, world health organization. Figures and facts about suicide. Available:
5. Korea NeuroPsychiatric Association. Textbook of neuropsychiatry. 2005. 2nd edition. Seoul: Joongang copy;(Korean).
6. OECD. OECD factbook 2011: Health status. 2011. 270–271.
7. Statistics Korea. Death rates for the 10 leading causes of death by age. Available: (Korean).
8. Routley VH, Ozanne-Smith JE. Work-related suicide in Victoria, Australia: a broad perspective. Int J Inj Contr Saf Promot. 2012. 47:131–134.
9. Takada M, Suzuki A, Shima S, Inoue K, Kazukawa S, Hojoh M. Associations between lifestyle factors, working environment, depressive symptoms and suicidal ideation: a large-scale study in Japan. Industrial health. 2009. 47:649–655.
10. Nakata A. Work hours, sleep sufficiency, and prevelance of depression among full-time employees: a community-based cross-sectional study. J Clin Psychiatry. 2011. 72(5):605–614.
11. Korea centers for disease control and prevention. Guide to the utilization of the data from the forth Korea National Health and Nutrition Examination Survey. 2010. Seoul: (Korean).
12. Virtanen M, Stansfeld SA, Fuhrer R, Ferrie JE, Kivimäki M. Overtime work as a predictor of major depressive episode: A 5-year follow-up of the Whitehall II study. PLoS ONE. 2012. 7(1):e30719.
13. Allen H, Slavin T, Bunn W. Do long workhours impact health, safety, and productivity at a heavy manufacturer? J Occup Environ Med. 2007. 49:148–171.
14. Son MA, Kong JO, Koh SB, Kim JY, Harma M. Effects of long working hours and the night shift on severe sleepiness among workers with 12-hour shift systems for 5 to 7 consecutive days in the automobile factories of Korea. J Sleep Res. 2008. 17:385–394.
15. Dahlgren A, Kecklund G, Akerstedt T. Overtime work and its effects on sleep, sleepiness, cortisol and blood pressure in an experimental field study. Scand J Work Environ Health. 2006. 32(4):318–327.
16. Park JS, Kim YH, Chung HK, Hisanaga N. Long workiing hours and subjective fatigue symptoms. Industrial Health. 2011. 39:250–254.
17. Dembe AE, Delbos R, Erickson JB. Estimates of injury risks for healthcare personnel working night shifts and long hours. Qual Saf Health Care. 2009. 18:336–340.
18. Ko G, Chan J, Chan A, Wong P, Hui S, Tong S, Ng SM, Chow F, Chan C. Association between sleeping hours, working hours and obesity in Hong Kong Chinese: the 'better health for better Hong Kong' health promotion campaign. International Journal of Obesity. 2007. 31:245–260.
19. Iwasaki K, Sasaki T, Oka T, Hisanaga N. Effects of working hours on biological funcions related to cardiovascular system among salesmen in a machinery manufactoring company. Industrial Health. 1998. 36:361–367.
20. Sasaki T, Iwasaki K, Oka T, Hisanaga N, Ueda T, Takada Y, Fujiki Y. Effects of working hours on cardiovascular-autonomic nervous functions in engineers in an electronics manufacturing company. Industrial Health. 1999. 37:55–61.
21. Persson R, Orbaek P, Ursin H, Kecklund G, Osterberg K, Akerstedt T. Effects of the implementation of an 84-hour workweek on neurobehavioral test performance and cortisol responsiveness during testing. Scand J Work Environ Health. 2003. 29(4):261–269.
22. Persson R, Orbaek P, Kecklund G, Akerstedt KT. Impact of an 84-hour workweek on biomarkers for stress, metabolic processes and diurnal rhythm. Scand J Work Environ Health. 2006. 32(5):349–358.
23. Varma A, Marott JL, Stoltenberg CD, Wieclaw J, Dolstad HA, Bonde JP. With long hours of work, might depression then lurk? A nationwide prospective follow-up study among Danish senior medical consultants. Scand J Work Environ Health. 2012. 38(5):418–426. Online-first-article. Available: abstract_id=3268. [cited January 2012].
24. Nakata A, Takahashi M, Irie M. Association of overtime work with cellular immune markers among healthy daytime white-collar employees. Scand J Work Environ Health. 2012. 38(1):56–64.
25. Goodwin R, Marusic A. Association between short sleep and suicidal ideation and suicide attempt among adults in the general population. SLEEP. 2008. 31(8):1097–1101.
26. Kohyama J. Sleep, serotonin and suicide in Japan. J Physiol Anthropol. 2011. 30(1):1–8.
27. Krakow B, Ribeiro JD, Ulibarri VA, Krakow J, Joiner TE. Sleep disturbances and suicidal ideation in sleep medical center patients. J Affect Disord. 2011. 131:422–427.
28. Fujino Y, Mizoue T, Tokui N, Yoshimura T. Prospective cohort study of stress, life satisfaction, self-rated health, insomnia, and suicide death in Japan. Suicide Life Threat Behav. 2005. 35(2):227–237.
29. Turvey CL, Conwell Y, Jones MP, Phillips C, Simonsick E, Pearson JL, Wallace R. Risk factors for late-life suicide: a prospective, community-based study. Am J Geriatr Psychiatry. 2002. 10(4):398–406.
30. Woo JM, Postolache TT. The impact of work environment on mood disorders and suicide: Evidence and implications. Int J Disabil Hum Dev. 2008. 7(2):185–200.
31. Lee W, Ha J. The association between nonstandard employment and suicidal ideation: data from the firstforth Korea National and Nutrition Examination Surveys. Korean J Occup Environ Med. 2011. 23(1):89–97.
32. Lorant V, Kunst AE, Huisman M, Costa G, Mackenbach J. Socio-economic inequalities in suicide: a European comparative study. Br J Psychiatry. 2005. 187:49–54.
33. Lorant V, Deliège D, Eaton W, Robert A, Philippot P, Ansseau M. Socioeconomic inequalities in depression: a meta-analysis. Am J Epidemiol. 2003. 157:98–112.
34. Moon DK. A meta-analysis on related protective variables on the suicidal ideation of older adults. Korean J Soc Welf Educ. 2012. 17:144–166.
35. Noh YH. Determinants of suicidal ideation: A microeconometric analysis. Korean J Health Econ Policy. 2007. 13(1):41–58.
36. Corcoran P, Nagar A. Suicide and marital status in Northern Ireland. Soc Psychiatry Psychiatr Epidemiol. 2010. 45:795–800.
37. Kposowa AJ. Marital status and suicide in the national longitudinal mortality study. J Epidemiol Community Health. 2000. 54:254–261.
38. Orui M, Kawakami N, Iwata N, Takeshima T, Fukao A. Lifetime prevelance of mental disorders and its relationship to suicidal ideation in a Japanese rural community with high suicide and alcohol consumption rates. Environ Health Prev Med. 2011. 16:384–389.
39. Song IH, Kim HJ. Depressive mood, suicidal ideation, and alcohol drinking behavior among married employees. Ment Health Soc Work. 2010. 36(12):5–34.
40. Hughes JR. Smoking and suicide: a brief overview. Drug Alcohol Depend. 2008. 98(3):169–178.
41. Druss B, Pincus H. Suicidal ideation and suicide attempts in general medical illnesses. Arch Intern Med. 2000. 160:1522–1526.
42. DeLeo D, Cerin E, Spathonis K, Burgis S. Lifetime risk of suicide ideation and attempts in an Australian community: Prevalence, suicidal process, and help-seeking behaviour. J Affect Disord. 2005. 86:215–224.
43. Nock MK, Borges G, Bromet E, Alonso J, Angermeyer M, Beautrais A, Bruffaerts R, Chiu WT, Girolamo G, Gluzman S, de Graaf R, Gureje O, Haro JM, Huang Y, Karam E, Kessler R, Lepine JP, Levinson D, Medina-Mora ME, Ono Y, Possada-Villa J, Williams D. Cross-national prevalence and risk factors for suicidal ideation, plans and attempts. Br J Psychiatry. 2008. 192:98–105.
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