WSIB Now Covers Chronic Mental Stress Injuries – What Employers Need to

October 9, 2018

By Jodi Gallagher Healy, Hicks Morley Hamilton Stewart Storie LLP

Photo by Kat Jayne from Pexels 

It used to be that Ontario’s workers compensation system only covered physical injuries at work, with some minor exceptions for traumatic mental stress injuries of first responders such as police and EMS.

As of January 1, 2018, the WSIB system has changed significantly to encompass certain chronic mental stress injuries arising from all workplaces covered by the WSIB system. There are transitional provisions that allow claims prior to January 1, 2018 in limited circumstances.

Including chronic mental stress claims under the WSIB system is a significant change for employers because it expands who will make WSIB claims, when Form 7 reporting will be required and when the WSIB will become involved in workplace situations such as alleged harassment and bullying. It could also have significant cost consequences for employers who participate in an experience rating program such as MAP, CAD-7 or NEER as well as impact an employer’s WSIB premiums under the new WSIB rate framework that is scheduled to come into effect in 2020.

Key Takeaway Points of the Chronic Mental Stress Policy

Here are the mechanics of how the new WSIB CMS policy works:

  • Workers will be granted entitlement for chronic mental stress if they have an appropriate diagnosis (e.g. depression or an anxiety disorder) and where the injury is caused by a “substantial work-related stressor” arising out of and in the course of employment. In many cases, workplace harassment or bullying will be a sufficient workplace stressor to trigger the policy.
  • The appropriate diagnosis must be made in accordance with the Diagnostic and Statistical Manual of Mental Disorders (“DSM”) and by a qualified regulated health care practitioner. This includes a family doctor, nurse practitioner, psychologist or psychiatrist.
  • Interpersonal conflicts generally will not give rise to entitlement unless they amount to workplace harassment or they result in conduct that a reasonable person would perceive as egregious or abusive.
  • The WSIB decision-maker must be satisfied, on a balance of probabilities, that the substantial work-related stressor(s) arose out of and in the course of employment and was the predominant cause of an appropriately diagnosed mental stress injury.
  • Predominant cause “means that the substantial work-related stressor is the primary or main cause of the mental stress injury.” The existence of stressors other than work doesn’t rule out a WSIB claim. 

What Employers Can Do to Minimize Liability under the CMS Policy

To reduce the risk  of WSIB claims related to CMS, employers should ensure that they:

  1. Understand how the WSIB reporting rules apply to chronic mental stress situations and ensure that all situations are reported to the WSIB in a timely way. Generally, if an employee goes to a doctor or nurse practitioner and/or is absent from work or requires modified duties for more than seven calendar days, the employer is required to file a Form 7 and pay the employee full wages for the day of injury. The WSIB can fine or prosecute employers who fail to report workplace injuries, which now includes chronic mental stress injuries.
  2. Ensure that supervisors and management are trained to understand that chronic mental stress injuries are now covered by WSIB and know their role in such claims. This means filing Form 7s, understanding that they cannot even unintentionally dissuade an employee from filing a CMS claim with the WSIB.
  3. Assess sources of workplace chronic mental stress as you would physical hazards and work to reduce or eliminate them. Help employees handle sources of workplace stress. This may mean providing employees with resiliency and respectful workplace training and providing a health and wellness program.
  4. Train supervisors and managers how to respond to harassment and bullying claims including to “document, document, document”.
  5. Actively manage CMS claims including at the initial entitlement and return to work phases. As with physical injury claims, the key to managing the cost and impact of CMS claims will be to proactively provide written offers of suitable work. This may mean thinking creatively about return to work plans and reassessing return to work plans more frequently to assess their continued success.


Jodi Gallagher Healy is a partner with Hicks Morley and practices from the firm’s London, Ontario office. She advises employers on all aspects of labour and employment law, with a focus on WSIB and human rights matters.


Knowledge. Clarity. Action.