A recent decision(1) of the Ontario Workplace Safety and Insurance Appeals Tribunal has significantly expanded the scope of entitlement for workplace events that cause traumatic mental stress. Traditionally, traumatic mental stress benefits were granted only when a claimant experienced a traumatic event which presented a real or implied threat to a person's physical wellbeing. In Decision 483/11 the tribunal held that a threat to a person's physical welfare is not required for a finding of entitlement to benefits based on traumatic mental stress.

The claimant in question was an educational assistant who sought benefits for mental stress after being falsely accused of striking a Grade 5 student in class. The claimant was suspended to allow the school to investigate the allegation and was reinstated after being exonerated by the investigation. However, the claimant was diagnosed with major depression and was unable to continue her duties.

The tribunal found that the false allegations and subsequent events were objectively unexpected and traumatic, and resulted in a disabling psychological condition. A report from the claimant's treating physician indicated that the claimant experienced flashbacks of the moment of her suspension, and avoided children and places such as schools and playgrounds. Medical evidence also showed that the claimant experienced sexual and emotional abuse in her childhood, memories of which were triggered by the incident.

In an earlier decision released in May 2011,(2) the tribunal found that the claimant would be entitled to benefits for traumatic mental stress, but for an apparent requirement in the applicable Workplace Safety and Insurance Board policy(3) that the traumatic event involve a real or implied threat to a person's physical wellbeing. The tribunal adjourned the claimant's application to receive submissions from the board on an apparent inconsistency between the board's traumatic mental stress policy and the Workplace Safety and Insurance Act 1997 on this point, as well as on inconsistencies within the board policy itself. The tribunal also asked the board to clarify whether a diagnosis of post-traumatic stress disorder (PTSD) is a prerequisite for entitlement under the board's policy.

In response to the tribunal's request, the board advised that a real or implied threat to a person's physical wellbeing is not required to find entitlement to traumatic mental stress benefits. The board also clarified that PTSD is not the only Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) diagnosis that can form the basis for entitlement; any Axis I diagnosis may suffice. After receiving the board's response, the tribunal granted the claimant benefits for traumatic mental stress.

Decision 483/11 is significant because it considerably widens the scope of compensable events in traumatic mental stress cases to situations that result in traumatic stress without the presence of a threat to physical wellbeing. As a result of this decision, employers should expect more claims for traumatic mental stress. However, employers can take some comfort in the fact that all claimants seeking entitlement to traumatic mental stress have a significant evidentiary burden to meet. To succeed in a traumatic mental stress claim, it must be demonstrated that:

  • the claimant was exposed to a workplace event that is identifiable, objectively traumatic and unexpected in the normal course of the worker's employment; and
  • a disabling psychological injury occurred as a result, as demonstrated by an Axis I DSM-IV diagnosis.

None of the parties to Decision 483/11 are seeking reconsideration or judicial review of the tribunal's decision.


(1) The decision can be accessed at http://canlii.ca/t/fmltw.

(2) Decision 483/11I, 2011 ONWSIAT 1231, [2011] OWSIATD 1012.

(3) Workplace Safety and Insurance Board, "Traumatic Mental Stress," Operational Policy Manual, OP 15-03-02.

For further information on this topic please contact Charlotte Willson at Heenan Blaikie LLP by telephone (+1 416 360 6336), fax (+1 416 360 8425) or email ([email protected]).