We hypothesised that the association between quality of leadership and mental distress would be stronger in Germany than in Denmark. The two countries differ in terms of working life cultures and labour markets, factors possibly mitigating the association of quality of leadership with mental distress. Data were based on the German Study on Mental Health at Work (2012–2017) and the Danish Work Environment Cohort Study (2000–2005 and 2005–2010), comprising 9,613 observations. A two-part model approach was employed, combining logistic and generalized linear regression models, with mental distress at follow-up as outcome variable. Heterogeneity of the country-specific estimates was assessed using a Cochran Q test. Among all participating employees, the logistic regression showed that higher quality of leadership was associated with lower mental distress (> 0) in both Germany and Denmark. This association was stronger in Germany, with the country difference being statistically significant (p = 0.036). Among employees with mental distress at follow-up, the generalized linear models revealed that quality of leadership was associated with decreased mental distress in Denmark, but not in Germany, with the country difference also being significant (p = 0.014). The inconsistent results did not support our hypothesis of a stronger association between quality of leadership and mental health in Germany. All results taken into consideration, the findings suggest that poor quality of leadership is associated with the development of mental distress in both countries. Further research is needed to examine the association between quality of leadership and mental health in other countries.

This article is published in the Journal "Scientific Reports" (2025).