Williams HR Law LLP

WSIB Finalizes Operational Policy on Chronic Mental Stress

November 2, 2017

[vc_row][vc_column width=”1/4″][vc_single_image image=”2294″ img_size=”large”][/vc_column][vc_column width=”3/4″][vc_column_text]When the Ontario government passed Bill 127, the Stronger, Healthier Ontario Act (Budget Measures), 2017 (“Bill 127”) in May 2017, it introduced significant amendments to the Workplace Safety and Insurance Act (the “WSIA”),

which we initially wrote about in an earlier blog post. The most significant of these changes for many employers was the extension of Workplace Safety Insurance Board (“WSIB”) benefit coverage to employees who suffer from chronic, work-related mental stress. This is a substantial change to the current landscape, whereby WSIB benefits have only been available for mental stress where the stress is traumatic in that it results from an acute reaction to a single sudden and unexpected event. After previously issuing a draft policy related to these WSIA amendments and considering stakeholder feedback, the WSIB has now finalized and approved a new policy, entitled “Chronic Mental Stress (Accidents on or After January 1, 2018)” (the “CMS Policy”). The WSIB has also now amended its existing Traumatic Mental Stress policy to help distinguish between traumatic and chronic mental stress. The policy changes will come into effect on January 1, 2018.

The Policy

For an employee to be entitled to WSIB benefits under the CMS Policy, three conditions must be met:

  1. The employee must have experienced a substantial work-related stressor;
  2. The work-related stressor must be the predominant cause of the injury; and
  3. An appropriate regulated health professional must provide a diagnosis based on the Diagnostic and Statistical Manual of Mental Disorders (the “DSM”), published by the American Psychiatric Association.

The employee must have experienced a substantial work-related stressor

The CMS Policy stipulates that employees will be entitled to benefits for chronic mental stress if the stress is caused by a “substantial work-related stressor”. A substantial work-related stressor must be “excessive in intensity and/or duration in comparison to the normal pressures and tensions experienced by workers in similar circumstances.” The CMS Policy lists workplace harassment as an example of a “substantial work-related stressor” that would generally qualify an individual for WSIB benefits.

The CMS Policy confirms that an enduring interpersonal conflict will not generally be considered a substantial work-related stressor, unless it amounts to workplace harassment (which is defined to include workplace bullying) or if it resulted in conduct that a reasonable person would consider egregious or abusive. The CMS Policy also confirms that benefits for chronic mental stress will not be available when the mental stress arises out of work-related decisions made by employers, such as decisions related to demotions, terminations, transfers of location and changes in working hours. If the chronic mental stress is the result of employer actions which are not related to the work function, however, workers will be entitled to benefits.

Although benefits will be limited to individuals whose stress is excessive as compared to other workers in similar circumstances, the CMS Policy clarifies that employees in jobs with a high degree of routine stress, where the employee has responsibility over life and death matters or the work takes place in extremely dangerous conditions, should not necessarily be denied compensation for chronic mental stress due to the nature of their work. Therefore, consistent exposure to a high degree of routine stress may qualify as a substantial work-related stressor.

The work-related stressor must be the predominant cause of the injury

The CMS Policy requires that the work-related stressor be the predominant cause of the mental stress injury. However, this does not mean that the work-related stressor must account for more than half of the cause of the injury, as “predominant” sometimes signifies. Rather, the work-related stressor must be the greatest single contributor to the mental stress injury, even if it is outweighed by all of the others combined.

An appropriate regulated health professional must provide a diagnosis

The mental stress injury must be diagnosed by a physician, nurse practitioner, psychologist, or psychiatrist. The diagnosis must be made according to the DSM, and may include, but is not limited to:

  • An anxiety disorder;
  • A depressive disorder;
  • Acute stress disorder;
  • Posttraumatic stress disorder; or
  • Adjustment disorder.


As chronic mental stress will now be a compensable workplace injury as of January 1, 2018, employers will be under an obligation to report those injuries when they occur, just as they must report a physical injury. The new CMS Policy will likely result in increased WSIB claims for many employers. However, because the WSIA limits employees’ right to sue for injuries that are compensated by WSIB benefits, it is possible that employers may be able to defend certain civil actions by employees who allege harassment and chronic mental stress in the workplace on the basis that the employee may not bring a civil action related to those allegations, as the proper venue for compensation related to those claims is the WSIB. Such claims may include damages for the tort of harassment (which is an independent cause of action in Ontario and includes workplace harassment) or the tort of intentional infliction of mental suffering, constructive dismissal due to a poisonous work environment, or discrimination that results in chronic mental stress. On the other hand, employers may face some additional challenges as the Bill 127 amendments will require employers to involve themselves in WSIB efforts to return covered workers to work, if possible, after the mental stress injury.

Employers will have to take a proactive approach to preventing chronic mental stress by identifying and addressing potential causes, which will be aided by the harassment policies workplaces have had to implement as a result of the Bill 132 amendments to the Occupational Health and Safety Act that came into force last fall. By taking steps to minimize mental stress injuries, employers can reduce the number of potential WSIB claims and experience advantages including increased employee productivity, engagement and attendance, and lower turnover.


This blog is provided as information and a summary of workplace legal issues.

This information is not intended as legal advice.