Objectives The World Economic Forum estimated that, by 2030, global costs of mental disorders are projected to reach US$6.0 trillion; about two thirds of these costs will be attributed to lost productivity related to disability. This brief article discusses factors that are related to the costs of mental illness in the workplace, identifies some of the workplace elements which could be targeted to reduce costs and explores examples of types of workplace interventions that can reduce costs.Methods We summarize the results of a Canadian research program using economic analyses to understand the costs of work disability related to mental disorders and cost-effective interventions.Results There are at least two main approaches to decrease the costs of mental disorders in the workplace. The first approach could be to decrease the prevalence of mental disorders among workers or the incidence of sickness absences. A second approach would be to increase access to treatment by addressing barriers to treatment. Both can have significant impacts to decrease costs.Conclusions Treatment can help workers experience mental disorders have higher productivity than they would have otherwise. By creating supportive workplace cultures through management training, organizations can potentially see a return through decreased sickness absences and higher productivity.