Effect of long working hours on psychological distress among young workers in different types of occupation

Background: We investigated how the association between long working hours and psychological distress varies across different employment and occupation types in young workers. Methods: Examining a nationally representative sample of 7246 Korean workers (3621 women) aged 15 to 40, we analyzed 23,492 observations spanning from 2016 to 2020. Psychological distress was measured using the Brief Encounter Psychosocial Instrument. We employed a generalized estimating equation to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Results: Of the total observations, 5.2% worked <35 h/week, 52.9% worked 35–40 h/week, 23.5% worked 41–48 h/week, 10.3% worked 49–54 h/week, and 8.2% worked ≥55 h/week. The OR (95% CI) of the association between long working hours and psychological distress was 1.38 (1.11–1.72) for <35 h/week, 1.47 (1.32–1.65) for 41–48 h/week, 1.74 (1.49–2.04) for 49–54 h/week, and 2.11 (1.75–2.55) for ≥55 h/week compared to 35–40 h/week. The OR (95% CI) of the association between working ≥55 h/week and psychological distress was significantly higher among wage workers (OR [95% CI]: 2.37 [1.94–2.89]) compared to self-employed workers (OR [95% CI]: 0.84 [0.52–1.36]). Additionally, the OR (95% CI) of the association between working ≥55 h/week and psychological distress was significantly higher among white-collar workers (OR [95% CI]: 3.24 [2.54–4.13]) compared to service/sales workers (OR [95% CI]: 1.22 [0.86–1.72]) or blue-collar workers (OR [95% CI]: 1.71 [1.10–2.67]). No clear gender differences were observed. Conclusion: Psychological distress caused by long working hours can be pronounced among white-collar and wage workers.