This commentary provides a summary of the four preceding research papers. Three of the four papers, those by Gilbert-Ouimet et al., Marchand and Durand, and Veitch, provide (Gilbert-Ouimet et al. 2011;Lippel 2011;Marchand and Durand 2011;Veitch 2011). Two of the papers, those by Marchand and Durand and by Gilbert-Ouimet et al., describe interventions focused on changing the psychosocial work environment to reduce the burden of mental health problems; another, by Veitch, overviews the relationship between the physical work environment and mental health; while a fourth, by Lippel, offers us a broad perspective on the regulations currently in place in Canadian provinces to protect the mental health of workers and the ways that law and policy can have the unintended consequences of increasing the illness and disability associated with mental health problems. The objective of this commentary is to summarize and tie together these research papers. In doing so, this commentary highlights the importance of research examining the relationship between working conditions and mental health problems, describes persistent challenges that need to be overcome in this research field and provides direction for future research in this area.From both organizational and public policy perspectives, evidence that negative changes in working conditions are associated with a subsequent increased risk in mental health problems (or that positive changes in the work environment are associated with a decreased risk of mental health problems) is important if the potential mental health effects, and their associated costs, are to be incorporated into decisions that will impact the work environment (Kuper and Marmot 2003;Macleod and Davey Smith 2003). In addition, intervention research focused on work environments (both physical and psychosocial) is particularly important as these interventions have the potential to have much larger impacts on mental health than those interventions that seek to change individuals' perceptions of, or reactions to, stress, or those that focus on the effective treatment of mental problems after they arise (LaMontagne et al. 2007a; Vézina et al. 2004).Seven years ago, in this journal, Vézina and colleagues (2004) called for more rigorous research focusing on identifying the dimensions of the psychosocial work environment that should (and could) be changed, the best ways to bring about these changes and common barriers encountered when implementing changes within workplaces. In the paper from Gilbert-Ouimet et al. (2011), Vézina's group has answered this call and, in doing so, provided valuable direction for those researchers brave enough to undertake intervention research. Through their rigorously documented development, implementation and evaluation of an intervention focused on reducing psychosocial work stress, we can see concrete examples of the types of changes that were undertaken within different workgroups and whether they resulted in transformations in the psychosocial work environment and, ul...