20260015

REPRESENTED by:

VIDEOCONFERENCE – NOVEMBER 14, 2025

HEARD by:

DATED:

NOVEMBER 21, 2025

The worker, through their representative, is objecting to the Case Manager’s decision dated

June 24, 2024, which denied initial entitlement to a mental stress injury for traumatic mental stress (TMS) and chronic mental stress (CMS).

On March 27, 2024, this Educational Assistant (EA) was physically attacked by a student. On

April 4, 2024, the worker sought medical attention from their family doctor and reported a mental stress injury to their employer. The worker attributed their psychological symptoms to various incidents involving students who threatened and/or assaulted them in the course of their employment. They were diagnosed with post-traumatic stress disorder (PTSD) and major depressive disorder (MDD).

In the decision dated June 24, 2024, the Case Manager denied initial entitlement to a mental stress injury on the basis that the incidents reported by the worker were not objectively traumatic, did not constitute a substantial work-related stressor, and the diagnoses received were not in accordance with the Diagnostic and Statistical Manual of Mental Disorders (DSM). The Case Manager also determined the date of injury as April 4, 2024. The decision was reconsidered and upheld on December 24, 2025, and

September 10, 2025.

The worker objected to the decision dated June 24, 2024, and this matter was referred to the Appeals Services Division for consideration.

Operational Policy Manual

Published

11-01-04 Determining the Date of Injury

April 9, 2021

15-03-02 Traumatic Mental Stress

February 29, 2024

15-03-14 Chronic Mental Stress

February 2, 2024

Reference

Workplace Safety and Insurance Appeals Tribunal (WSIAT) Medical Discussion Paper titled

Post Traumatic Stress Disorder prepared by Dr. D Whitney, originally published in February 2010, and revised in September 2015 and 2022.

PRELIMINARY ISSUE

As part of my review, I will also review the date of injury as I note the worker representative requested it be reviewed in their December 15, 2024 submission. As I consider this issue to be intertwined to the issue of initial entitlement, I find it within my jurisdiction to address the date of injury as part of this appeal.

I reviewed the file and noted the employer has not returned the participant forms for the issue under appeal and has not provided any further information in response to the Intent to Object or Appeals Readiness Forms. The employer has not demonstrated any intent to participate in this appeal. I have therefore determined it would not prejudice the employer or result in administrative unfairness by addressing this issue as part of initial entitlement.

ANALYSIS

I have carefully considered all of the available information, legislation and relevant operational policies in reaching this decision.

For the reasons that follow, I find there is entitlement to benefits for PTSD and MDD under the TMS policy. The date of injury is March 27, 2024.

Worker’s position

The worker representative submits the worker is entitled to benefits for a mental stress injury under the TMS policy. They contend the worker was involved in multiple traumatic events where they were the object of physical violence, and which led to the diagnoses of PTSD and MDD. They cite a Workplace Safety and Insurance Appeals Tribunal (WSIAT) medical discussion paper and prior WSIAT decision in support of their position.

In the alternative, they are seeking entitlement to a mental stress injury under the CMS policy. They contend the circumstances of the case exceed the standard of predominant cause. The worker was involved in incident which were clearly and precisely identifiable, and involved behavior considered egregious and abusive.

The remedy being sought is the allowance of initial entitlement for a mental stress injury.

Employer’s position

The employer is not participating in the appeal and did not provide any submissions for my review.

Assessment and Findings

Entitlement to TMS

For the reasons that follow, I find the policy requirements for TMS are met.

To consider the entitlement to TMS, I turned to Policy 15-03-02 (Traumatic Mental Stress), which states a worker is entitled to benefits for traumatic mental stress arising out of and in the course of the worker’s employment. A worker is not entitled to benefits for traumatic mental stress caused by decision or actions of the worker’s employer relating to the worker’s employment, including a decision change to the worker to be performed or the working conditions, to discipline the worker or to terminate the employment.

A worker will generally be entitled to benefits for traumatic mental stress if an appropriately diagnosed mental stress injury is caused by one or more traumatic events arising out of and in the course of the worker’s employment.

Is there an appropriately diagnosed mental stress injury?

Policy 15-03-02 (Traumatic Mental Stress) provides that before any traumatic mental stress claim can be adjudicated, there must be a diagnosis in accordance with the DSM which may include, but is not limited to:

acute stress disorder
posttraumatic stress disorder
adjustment disorder, or
an anxiety or depressive disorder

Having reviewed the evidence, I find the worker received a diagnosis in accordance with the DSM. The Health Professional’s Report for Occupational Mental Stress (Form CMS8) completed by the family doctor dated April 4, 2024, confirms a diagnosis of severe major depressive episode, severe anxiety, and “query PTSD”. A September 3, 2024 Attending Physicians Statement of Disability also completed by the family doctor provided a diagnosis of PTSD. And lastly, the psychological assessment report dated

May 6, 2025, confirms the worker met the DSM diagnostic criteria for PTSD and MDD.

In my view, the available clinical documentation satisfies the requirement for a DSM diagnosis, and I find this criterion met.

Is there evidence of one or more traumatic events?

According to Policy 15-03-02 (Traumatic Mental Stress), in order to consider entitlement for mental stress related to one or more traumatic events, the WSIB decision-maker must identify that one or more traumatic events occurred. A traumatic event may be a result of a criminal act or a horrific accident, and may involve actual or threatened death or serious harm against the worker, a co-worker, a worker’s family member, or others. In most cases a traumatic event will be sudden and unexpected.

In all cases, the event(s) must arise out of and occur in the course of employment, and be clearly and precisely identifiable, and objectively traumatic. This means that the decision-maker, after assessing and weight all relevant and available evidence, including any provided by the worker, co-workers, supervisory

staff, or others, is satisfied that the event(s) more likely than not occurred, and the event(s) is/are generally accepted as being traumatic.

Traumatic events include, but are not limited to:

witnessing a fatality or horrific accident
witnesses or being the object of an armed robbery
witnessing or being the object of a hostage-taking
being the object of physical violence
being the object of death threats
being the object of threats of physical violence where the worker believes the threats are serious and harmful to self or others (e.g. bomb threats or confronted with a weapon)
being the object of workplace harassment that includes physical violence or threats of physical violence (e.g., the escalation of verbal abuse into traumatic physical abuse), and
being the object of workplace harassment that includes being placed in a life-threatening or potentially life-threatening situation (e.g. tampering with safety equipment; causing the worker to do something dangerous)

The worker must have suffered or witnessed the work-related traumatic event(s) first-hand, or heard the work-related traumatic event(s) first-hand through direct contact with the traumatized individual(s), e.g., speaking with the victim(s) on the radio or telephone as the traumatic event(s) is/are occurring.

The policy further states that some workers, over a period of time, may be exposed to multiple traumatic events. If a worker experiences traumatic mental stress because of the most recent traumatic event, entitlement may be in order even if the worker may experience these traumatic events as part of the employment and was able to tolerate the past traumatic events. A final reaction to a series of traumatic events is considered to be the cumulative effect.

In considering the entitlement for the cumulative effect, decision-makers will rely on clinical and other information supporting that multiple traumatic events led to the worker’s current psychological state.

In the Worker’s Report of Injury or Illness (Form 6) dated April 5, 2024, the worker reported they have been verbally and physically assaulted by multiple students on multiple occasions. They have also witnessed co-workers attacked on multiple occasions where visible and disturbing injuries were sustained. In their submissions and testimony, the worker detailed several events they felt were most significant from 2023 to 2024.

February 28, 2023 incident

On this date, the worker was monitoring students on the bus at the end of the school day. They testified they were the only EA on the bus, and that there were several kids present that required support. During the bus ride, an 8-or-9-year-old male student old was being disruptive and standing in the aisle. The worker told the student he needed to sit in his seat and proceeded to sit next to him to prevent him from moving back to the aisle. The student began repeatedly pushing and punching the worker in the back.

The worker told him to stop, but the student said he didn’t have to listen to them. The student’s sister voiced her support for her brother, also stating that he didn’t have to listen to the worker. The worker advised they remained next to the student as they believed he would return to the aisle and posed a safety risk to the other students. The worker testified they sustained ongoing punching for the remainder of the ride which was approximately 15 minutes.

The worker testified they reported the incident right away to their supervisor. They were told they didn’t handle the situation properly according to their training, and that they should have utilized behavior management systems. The worker testified that this typically requires 2 other people helping, and that they were alone in a confined space on a moving bus. They described how this response made them feel as though they were at fault in the incident. They also felt significant distress that other students witnessed this student assault them over a prolonged period of time. That night they had bad dreams and nightmares of being assaulted.

The Employee Workplace Incident Report dated February 28, 2023, provides the same version of the events. Student aggression and/or violence was confirmed, and the education/training of staff was indicated to be the corrective and/or prevention actions taken.

November 2, 2023 incident

The worker testified that on this date they were working with another 8-or-9-year-old male student at their desk. The student became agitated as they did not want to complete the academic task. The student started to scream, kick, and punch the worker. The teacher redirected the student out into the hall with the worker where he continued to kick and punch the worker’s legs. Two other teachers came out into the hall to assist. One of the teachers told the worker to duck into the washroom and they would handle the student. The student broke free and ran after the worker to the bathroom door where they started kicking the door and yelling. The worker was able to hold the door shut from the other side until the student was eventually redirected into a classroom.

The worker advised they sought medical attention with their family doctor following this incident. They took a stress leave from work where their family doctor recommended accommodations where the worker be placed with students who did not have a significant history of violence or aggression.

I note there was no documentation from the employer provided regarding this incident. March 18, 2024 incident

The worker testified that on this date they were assigned with a student who was escalated. The student was another 8-to-9-year-old boy. They advised that another EA was present during a behavioral outburst where the student had gotten a hold of a plastic milk crate and was attempting to hit them with it. The student grabbed the worker’s arm and made verbal threats, stating that they would break their arm and that they knew how. When the milkcrate was removed from the student, he began kicking the worker’s legs.

The student proceeded towards the gymnasium and the EAs followed. At point the student then charged at the worker, yelling expletives and calling them names. Another EA was able to assist but the student knocked this EA down on the floor. The student then ran to the library where they climbed to the top of a bookshelf and found metal rods being stored. The student picked up a metal rod, aimed it like a gun at the worker and said they were going to shoot them, and they knew how. The worker moved well out of the way before the student threw the pole down on the floor.

The worker testified that the student got down and was redirected to the office. They were told to take a break before returning to another assignment.

Documentation received from the employer including emails and an Employee Workplace Incident Report dated March 18, 2024, provide a description of the incident largely in keeping with the worker’s reported version of events.

March 27, 2024 incident

The worker testified that on March 27, 2024, they were monitoring a student at recess. They confirmed this was the same student that had recently climbed the bookshelf in the library. They were told to follow the student outside but to keep their distance. During this time the student yelled expletives at them, called them names and said they hated them. The student later requested to go inside to change his shoes. The acting Vice Principal was nearby, and the worker relayed the request on the radio. In response the vice principal shook their head in a “no” motion. This enraged the student who ran and lunged at the worker, grabbing the top of their head by the hair close to the scalp and pulling them forward while screaming he hated them with profanities. The Vice Principal ran over and assisted in removing the student from the worker. The worker took a break before finishing the rest of their shift.

The Employee Workplace Incident Report dated March 28, 2024, provides a similar version of the incident. Student aggression and/or violence was confirmed, and the education/training of staff was indicated to be the corrective and/or prevention actions taken.

The worker representative contends the violence experienced by the worker was clearly identifiable and objectively traumatic. I agree with this position. It is undisputed that the worker was the object of physical violence and threats while in the course of their work duties. I find the above-described incidents to be objectively traumatic given the worker experienced actual physical violence and their personal safety was at risk. In making my findings I afforded weight to the worker’s testimony. I found their description of the events to be detailed, credible, and consistent with contemporaneous documentation.

I also considered the WSIAT decision referenced by the worker representative to support the allowance of entitlement to health care benefits for a mental stress injury. However, it is important to note I am not bound by prior WSIAT decisions. Each case is decided on its own merits using the available evidence in the file and relevant policies.

The WSIAT decision 1741/21 involved an EA who experienced an onset of psychological symptoms following an incident where a student had a physical outburst. The worker was punched, kicked, and stabbed in the leg with a pencil. The Panel found the incident was considered objectively traumatic due to the element of concern for the worker’s personal safety, and for the safety of the students under their care. This finding was in keeping with prior Tribunal decisions that require an event to be considered traumatic by a neutral observer. The Panel found there is no requirement that the mental stress incident be analogous to the examples set out in Policy 15-03-02 (Traumatic Mental Stress).

The operating area found the above-described incidents did not involve behavior considered egregious or abusive. They concluded these events were not excessive in intensity or duration in comparison to the normal pressures and tensions experiences by workers in similar circumstances. I accept that the occupation of EA involves dealing with students with various intellectual, social, and emotional challenges, and that these students may exhibit behaviors including aggression, impulsivity, and disruption. I also acknowledge that these types of behaviors have become more commonplace in schools. However, I find that this does not diminish the traumatic nature of these types of incidents where the personal safety of school staff and students is at risk. I disagree with the notion that workers in this profession should expect to encounter and endure ongoing targeted physical violence.

Is there evidence the mental stress injury was work-related?

I find the worker’s diagnosed PTSD and MDD was directly caused by the cumulative effect of the above-described incidents. In my view, while the medical evidence supports an onset of psychological

symptoms in the fall of 2023, it is clear the worker sustained a final reaction following the March 27, 2024 incident which culminated an appropriately diagnosed mental stress injury.

I note the operating area did not accept the diagnoses of PTSD or MDD. They found the medical information from the family doctor on April 4, 2024, did not support a diagnosis in keeping with the DSM. They further determined that subsequent medical documentation from the family physician and psychologist did not support a clear temporal relationship between the workplace incidents and the diagnosed mental stress injuries. I arrived at a different conclusion. In my view, the clinical evidence is clear the worker developed PTSD and MDD as a direct result of multiple traumatic events at work.

To understand PTSD, its etiology, and work-relatedness, I referred to the WSIAT Medical Discussion Paper titled “Post Traumatic Stress Disorder” authored by Dr. Whitney. While the WSIB is not bound by information or opinions expressed in a discussion paper, information provided by a paper may be reviewed and considered.

According to the discussion paper, to meet the diagnostic threshold for PTSD in adults, there must be a specific cluster of psychological symptoms and impairment, and these symptoms must persist for more than one month.

The worker sought medical attention with their family doctor on April 4, 2024, approximately one week after the final workplace incident on March 27, 2024. The Form CMS8 completed at the visit confirms the diagnostic impression of major depressive episode, severe and anxiety, and query PTSD.

I interpreted the “query PTSD” diagnosis provided by the family doctor on April 4, 2024, to mean the worker was exhibiting a constellation of symptoms in keeping with PTSD, however, the duration of symptoms at that point meant they fell short of the diagnostic requirements. The family doctor provided examples of symptoms including but not limited to excessive worry, irritability, intrusive re-experiencing symptoms, hypervigilance and avoidance behaviors.

The Attending Physicians Statement of Disability dated September 3, 2024, confirms a diagnosis of PTSD. The worker testified they continued to experience ongoing psychological symptoms that did not abate, and they continued to remain off work. In my view, it is clear the worker’s symptoms continued to persist beyond one month, and the diagnostic criteria of PTSD was established.

A comprehensive psychological assessment was subsequently completed on April 9, 2025. The report dated May 6, 2025, confirms the diagnoses of PTSD and MDD. The psychologist endorsed a clinical impression that the worker’s mood and traumatic stress symptoms were directly related to their cumulative occupational exposure while working as an EA. No other sources or significant contributors to the worker’s mental stress injury were identified, and there was no history of any pre-existing psychological conditions.

I accepted and placed significant weight on the clinical impressions outlined in the psychological report dated May 6, 2025. I find the psychologist who conducted the assessment is duly qualified to provide opinions on the cause of psychological conditions. Furthermore, there is no alternate opinion from a psychiatrist or psychologist that contradicts the clinical impression that the worker’s PTSD and MDD is work-related.

In summary, in keeping with Policy 15-03-02 (Traumatic Mental Stress), I find the worker is entitled to health care benefits for PTSD and MDD stemming from the cumulative effect of multiple traumatic incidents which arose out of and in the course of their employment. Entitlement to benefits flowing from

this decision is remitted to the operating area for further review and is subject to the usual rights of appeal.

Entitlement to CMS

As discussed above, I found the entitlement criteria was satisfied for TMS. Accordingly, I find it is not necessary to proceed in reviewing the issue of whether the worker’s case meets the policy criteria of CMS, given initial entitlement to a mental stress injury has already been allowed.

Date of Injury

I find the date of injury is March 27, 2024. My reasons for why are outlined below.

To review the issue of the date of injury, I turned to Policy 11-01-04 (Determining the Date of Injury) which confirms the date of injury can refer to the date of an actual accident, of first medical attention, or of diagnosis.

In a chance event claim, which occurs when an identifiable unintended event causes an injury, the date of injury is the date of the actual incident. In a gradual onset disablement claim, the date of injury is established using the date of first medical attention which led to the diagnosis, or the date of diagnosis, whichever is earlier.

The Case Manager determined the date of injury to be April 4, 2024, in keeping with a gradual onset disablement claim. They concluded this was the date the worker was diagnosed with an occupational mental stress injury. For the reasons that follow, I arrived at a different conclusion.

Neither Policy 11-01-04 (Determining Date of Injury) or Policy 15-03-02 (Traumatic Mental Stress) provides specific guidance on determining the date of injury for mental stress claims.

In the circumstances before me, the worker is claiming a mental stress injury arising from a cumulative effect of multiple separate incidents. These incidents were detailed above and will not be repeated here. In my view, each incident is considered a chance event accident where an identifiable event causes an injury. Therefore, I find the date of the event, or in a situation where there is a cumulative effect of multiple events, the last event should be used at the accident date.

As discussed above, I accepted the worker sustained a mental stress injury resulting from a series of traumatic events. The final event occurred on March 27, 2024, and precipitated the worker’s layoff and led to the diagnoses of PTSD and MDD. Therefore, I find March 27, 2024, to be the most appropriate date of injury.

In summary, in keeping with Policy 11-01-04 (Determining Date of Injury), I find the date of injury is March 27, 2024.

CONCLUSION

I conclude the following:

Initial entitlement to PTSD and MDD under the TMS policy is allowed.
The date of injury is March 27, 2024.

The worker’s objection is allowed.

DATED NOVEMBER 21, 2025

E. Parsons

Appeals Resolution Officer Appeals Services Division

Worker v. Employer, 2025 CanLII 152660

Case Summary