Mental disorders are common among employees, are associated with reduced productivity, and are often untreated. A key theme in the workplace mental health (WMH) arena is the need to increase employee diagnosis and treatment rates, on the assumption that this will improve wellbeing and productivity. Furthermore, WMH initiatives are seen as a strategic approach to increasing treatment-seeking in the population, given the huge proportion of people who participate in the labour force and the large amounts of time people spend at work.

It is generally taken for granted that people with untreated mental disorders have adverse outcomes that could be averted by treatment. Additionally, it is commonly assumed that people with mental disorders who do not perceive a need for treatment have low levels of mental health literacy, and that they need to be educated and encouraged to recognise the symptoms of mental disorders and seek treatment.

Increasing treatment rates among workers, it is claimed, will deliver not only improvements in population mental health but also substantial economic benefits for employers (e.g. a five-fold return on investment) and for society (including productivity growth and reduced healthcare and disability pension costs). This win-win perspective dominates the WMH literature and the thriving WMH training and consultancy industry.

However, the epidemiological and economic evidence-base for these assumptions and claims is weak and flawed. The evidence-base for screening, which is often advocated, is even more problematic.

Counterintuitively, several studies have found that wellbeing and productivity are higher among untreated/never-treated employees than currently/previously treated employees. However, such evidence is generally ignored, and sometimes it is misrepresented.

The superior outcomes of untreated people are partly due to confounding by severity and comorbidity: there is a strong association between severity/comorbidity and treatment-seeking. However, my analysis of data from the Australian National Survey of Mental Health and Wellbeing reveals that this is also the case with stratification by severity.

Additionally, treatment has potential iatrogenic harms, including adverse effects of psychiatric drugs and psychotherapy, and the potentially stigmatising and disempowering effects of diagnostic labels and treatment. However, this is rarely acknowledged.

Furthermore, methodological sloppiness is common in WMH research. For example, physical disorders, which frequently coexist with mental disorders, are also associated with substantial productivity decrements, but these are often attributed to mental disorders.

The narrow focus on increasing diagnosis and treatment locates the problem within individuals and deflects attention from the impact of working conditions on mental health and from broader social determinants of mental health. Some WMH documents, policies, and programs pay lip-service to these, but nevertheless focus squarely on individualised assessment, diagnosis, and treatment – which in the real world very often means antidepressants and other psychotropic drug treatment.

The comfortable fit of the workplace mental health agenda with neoliberal ideology makes it a powerful driver of overdiagnosis and unnecessary, potentially harmful treatment.