Work Engagement as a Predictor of Onset of Major Depressive Episode (MDE) among Workers, Independent of Psychological Distress: A 3-Year Prospective Cohort Study

Kotaro Imamura; Norito Kawakami; Akiomi Inoue; Akihito Shimazu; Akizumi Tsutsumi; Masaya Takahashi; Takafumi Totsuzaki

doi:10.1371/journal.pone.0148157

Work Engagement as a Predictor of Onset of Major Depressive Episode (MDE) among Workers, Independent of Psychological Distress: A 3-Year Prospective Cohort Study

PLoS One. 2016 Feb 3;11(2):e0148157. doi: 10.1371/journal.pone.0148157. eCollection 2016.

Authors

Kotaro Imamura¹, Norito Kawakami¹, Akiomi Inoue², Akihito Shimazu¹, Akizumi Tsutsumi³, Masaya Takahashi⁴, Takafumi Totsuzaki⁵

Affiliations

¹ Department of Mental Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
² Department of Mental Health, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Japan, Kitakyushu, Japan.
³ Department of Public Health, Kitasato University School of Medicine, Sagamihara, Japan.
⁴ Health Administration and Psychosocial Factor Research Group, National Institute of Occupational Safety and Health, Japan, Kawasaki, Japan.
⁵ Uchisaiwaicho Medical Center, Mizuho Health Insurance Society, Tokyo, Japan.

Abstract

Objective: This study investigated work engagement as a baseline predictor of onset of major depressive episode (MDE).

Methods: The study used a prospective cohort design, conforming to the STROBE checklist. Participants were recruited from the employee population of a private think tank company (N = 4,270), and 1,058 (24.8%) of them completed a baseline survey, of whom 929 were included in this study. Work engagement and psychological distress at baseline were assessed as predictor variables. MDE was measured at baseline and at each of the follow-ups as the outcome, using the web-based, self-administered version of the Japanese WHO-CIDI 3.0 depression section based upon DSM-IV-TR/DSM-5 criteria. Cox discrete-time hazards analyses were conducted to estimate hazard ratios (95% confidence intervals CIs).

Results: Follow-up rates of participants (N = 929) were 78.4%, 67.2%, and 51.6% at 1-, 2-, and 3-year follow-ups, respectively. The association between work engagement at baseline and the onset of MDE was U-shaped. Compared with a group with low work engagement scores, groups with the middle and high scores showed significantly (HR = 0.19, 95% CI = 0.05 to 0.64; p = 0.007) and marginally significantly (HR = 0.48, 95% CI = 0.20 to 1.15, p = 0.099) lower risks of MDE, respectively, over the follow-ups, after adjusting for covariates. The pattern remained the same after additionally adjusting for psychological distress.

Conclusions: The present study first demonstrated work engagement as an important predictor of the onset of MDE diagnosed according to an internationally standard diagnostic criteria of mental disorders.

Publication types

Clinical Trial
Comparative Study
Research Support, Non-U.S. Gov't

MeSH terms

Adult
Depression / epidemiology*
Depression / physiopathology
Female
Humans
Japan / epidemiology
Male
Middle Aged
Prospective Studies
Stress, Psychological / epidemiology*
Stress, Psychological / physiopathology
Work Performance*

Grants and funding

The present study was supported by a Grant-in-Aid for Scientific Research on Innovative Areas (Research in a Proposed Research Area) 2009–2013 (No. 4102-21119001) from the Ministry of Education, Culture, Sports, Science and Technology, Japan (http://www.mext.go.jp/a_menu/shinkou/hojyo/main5_a5.htm), The KAKENHI Grant Number 26253042 & 26860433 from the Japan Society for the Promotion of Science (https://www.jsps.go.jp/j-grantsinaid/), and the Health and Labor Sciences Research Grant 2015–2017 (H27-Rodo-Ippan-004) from the Ministry of Health, Labour and Welfare, Japan. (http://www.mhlw.go.jp/stf/seisakunitsuite/bunya/hokabunya/kenkyujigyou/index.html). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.