Reviewed by the clinical team at Aref Psychotherapy — a team of Registered Psychotherapists serving clients across Canada.
You’ve been through something at work that’s left a real mark. Maybe it was a single traumatic event you can’t shake. Maybe it’s been years of a toxic workplace wearing you down. Either way, you’re trying to figure out if WSIB actually covers mental health — and if so, how to file a claim without making a mistake that gets it denied.
The short answer is yes, WSIB covers mental stress injuries in Ontario. The longer answer is that the process is more nuanced than filing a claim for a physical injury, and most mental stress claims get denied not because the injury isn’t real, but because something procedural goes sideways.
This guide walks you through exactly how to file a WSIB mental stress claim in Ontario — what paperwork you need, what the deadlines are, which form to use, the common mistakes that get claims rejected, and what happens after you submit everything.
Can You File a WSIB Claim for Mental Stress?
Yes. Since January 1, 2018, Ontario’s Workplace Safety and Insurance Act (WSIA) has allowed workers to file claims for mental health injuries caused by work — not just physical injuries. That was a big shift. Before 2018, unless you were a first responder (covered earlier under Bill 163) or you had a mental injury secondary to a physical injury, mental health claims were mostly denied outright.
Now, three distinct mental health claim pathways exist under WSIB:
- Traumatic mental stress — caused by a specific workplace event
- Chronic mental stress — caused by ongoing workplace stressors over time
- First responder PTSD — covered under presumptive legislation
Each has different criteria. Picking the right pathway matters.
The Three Types of WSIB Mental Stress Claims
These aren’t interchangeable. Filing under the wrong one is one of the most common reasons for denial.
Traumatic Mental Stress (TMS). A mental health injury caused by one or more specific traumatic events at work. Classic examples: witnessing a serious injury or death, being physically attacked or threatened, being held up in a robbery, being a bystander to severe workplace violence. Governed by WSIB Operational Policy 15-03-02.
Chronic Mental Stress (CMS). A mental health injury caused by a substantial work-related stressor sustained over time. The most common example is workplace harassment or bullying. Also covers sustained exposure to unreasonable workloads, toxic management, or discrimination. Governed by WSIB Operational Policy 15-03-14.
First Responder PTSD. Presumptive coverage for firefighters, police, paramedics, nurses providing direct patient care, corrections officers, dispatchers, and others in designated occupations. For this pathway, PTSD is assumed to be work-related unless proven otherwise. If you’re a first responder, see our complete guide to first responder PTSD in Ontario for the full list of 20 covered occupations and the claim process.
There’s also psychotraumatic disability — mental health conditions that develop after a physical workplace injury. Different pathway, governed by a separate policy, but worth knowing exists.
Before You File — What You Need to Have Ready
Filing Form 6 without preparation is how most mental stress claims start off on the wrong foot. Here’s what to have in place first:
A DSM-5 diagnosis from a qualified health professional. WSIB requires this for every mental stress claim. More on who qualifies in the next section.
Documentation of the workplace events or conditions. Dates, locations, who was involved, what happened. For traumatic mental stress, this is usually one event. For chronic mental stress, this might be a timeline of incidents spanning months or years.
Records of when you reported the incident to your employer. Emails, texts, HR communications, anything showing you told someone. This becomes important later if the employer disputes the claim.
Employment records. Your start date, your role, any changes to your duties, any HR disciplinary actions — WSIB may ask for these.
Your own written narrative. Your account, in your own words, of what happened and how it’s affected you. You’ll use this when filling out Form 6 and when talking with your case manager.
A list of any pre-existing mental health conditions (if applicable). Don’t hide them — WSIB will find out anyway from your medical records. Being upfront works in your favour.
Taking a week or two to gather this before you file is almost always better than rushing and leaving gaps.
Getting a DSM-5 Diagnosis — The One Thing Everyone Misses
This is the step most articles skip over, and it’s where many claims stall before they start.
WSIB requires your mental health injury to be diagnosed by a qualified health professional according to the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition). For traumatic mental stress and chronic mental stress claims, WSIB accepts diagnoses from:
- Physicians (including family doctors)
- Nurse practitioners
- Psychologists
- Psychiatrists
For First Responder PTSD claims under presumptive coverage, the bar is higher — the diagnosis must come from a psychologist or psychiatrist specifically. Family doctors and nurse practitioners can’t trigger the presumption.
Common DSM-5 diagnoses that support mental stress claims include:
- Post-traumatic stress disorder (PTSD)
- Acute stress disorder
- Adjustment disorder
- Major depressive disorder
- Generalized anxiety disorder
Your diagnosis doesn’t need to be PTSD specifically. The key is that a qualified professional has formally diagnosed a DSM-5 condition and documented that it’s work-related.
Important: Registered Psychotherapists (like our team at Aref Psychotherapy) can provide therapy for mental stress injuries, but we don’t diagnose. If you need a diagnosis for your WSIB claim, your family doctor or a psychologist is usually the fastest starting point.
How to File Form 6 — Step by Step
Form 6 is the Worker’s Report of Injury/Disease. It’s the form you submit to start any WSIB claim. It was originally designed for physical injuries, which means some fields don’t fit perfectly for mental stress claims — you’ll need to use the “Additional Information” section at the end to add context.
Here’s how to file:
Step 1 — Tell your employer. This happens before the form. You’re required to report the workplace injury to your employer as soon as possible. For mental stress, this can be your supervisor, HR, a peer support coordinator, or occupational health. Get it in writing (email or text) so there’s a record.
Step 2 — Get your Form 6. Download it from the WSIB website or file online through WSIB’s online services portal. You can also call 1-800-387-0750 to request a paper copy.
Step 3 — Fill in the basic information. Your name, SIN, contact details, employment details. Straightforward.
Step 4 — Describe the injury. For “area of body injured,” write “psychological” or the specific diagnosis if you have one. For “how the injury happened,” briefly describe the event(s). For mental stress, one line isn’t enough — you’ll expand in the next step.
Step 5 — Use the Additional Information section. This is critical for mental stress claims. Expand on what happened:
- For TMS: describe the specific traumatic event(s) in detail — what happened, where, when, who was involved
- For CMS: provide a timeline of the stressors, specific incidents, dates and witnesses where possible
- For First Responder PTSD: reference your occupation and state that you’re filing under the presumptive legislation
Step 6 — Attach supporting documents. Medical reports, incident reports, HR emails, witness statements — anything that supports your claim. WSIB accepts attachments with the online form.
Step 7 — Submit and keep copies. Submit Form 6 online (fastest) or by mail. Keep a copy of everything you submit plus the submission confirmation.
Step 8 — Your employer submits Form 7. Within three business days of learning about the injury, your employer is legally required to submit their version (Form 7). You don’t control this, but you can follow up if it hasn’t been filed.
Step 9 — Your health professional submits Form 8. Your doctor or nurse practitioner submits their report (Form 8) directly to WSIB. Remind them if needed — WSIB won’t adjudicate without it.
What Happens After You File — the Adjudication Timeline
Filing is just the start. Here’s what comes next:
Within days. WSIB sends you a claim number and assigns an adjudicator (decision-maker).
1–2 weeks. Your adjudicator gathers documentation — Form 7 from your employer, Form 8 from your healthcare provider, and any additional records.
2–6 weeks. Your adjudicator may contact you to ask follow-up questions. This is standard. Answer honestly, keep records of every call.
Within 14 days of having complete documentation. Straightforward claims get a decision. Complex claims — and most mental stress claims are complex — can take weeks or months longer. Expect 2–3 months as a realistic timeline for a mental stress claim.
If approved. You’ll receive a letter outlining your benefits. This can include wage replacement, funded therapy, medication coverage, and return-to-work support. Therapy is typically delivered through the Community Mental Health Program or an approved private clinician. See our guide on what to expect from virtual WSIB therapy in Ontario for what happens next.
If denied. You’ll receive a letter explaining the reasons. You have six months to file a Notice of Objection. The Office of the Worker Adviser provides free help for non-unionized workers.
Why Mental Stress Claims Get Denied (and How to Avoid It)
Knowing the common reasons for denial is how you avoid becoming one. The top five:
1. The “predominant cause” test failed. For CMS claims especially, WSIB must be satisfied that the work-related stressor was the main cause of your mental health condition. If they believe outside factors (personal life events, pre-existing conditions) played a bigger role, the claim fails. Avoid this by: providing clear documentation of the workplace stressors and their timing relative to symptom onset.
2. The injury falls into the “employer decisions” exclusion. PTSD or depression caused by being disciplined, fired, demoted, passed over for promotion, or otherwise subject to management decisions is not covered — even if those decisions felt unfair. Avoid this by: framing your claim around the workplace events themselves (harassment, traumatic incidents, unreasonable conditions), not around management actions.
3. No DSM-5 diagnosis. Without a formal diagnosis from a qualified health professional, your claim cannot be adjudicated. Avoid this by: getting the diagnosis before or immediately after filing.
4. Filed outside the six-month deadline. Most mental stress claims must be filed within six months of the injury or diagnosis. Miss it and the default answer is no, even though the WSIB can extend the deadline in some cases. Avoid this by: filing as soon as you have a diagnosis, not waiting for “the right time.”
5. Not enough documentation. For CMS claims, vague timelines or lack of specifics about the workplace stressors is a common fail point. Avoid this by: documenting as you go, keeping emails, and providing dates and witnesses wherever possible.
What If I’ve Missed the Six-Month Deadline?
It’s not automatic, but time limits can be extended. The Office of the Worker Adviser notes that WSIB will extend the deadline in several circumstances, including:
- You were mentally or physically incapable of filing (e.g., hospitalized, in crisis)
- Serious personal health or family events prevented filing
- Your employer made you afraid to report
- WSIB policy or the law has since changed to your benefit
File the claim anyway. Include a written explanation of why it was filed late, supported by medical records or other documentation. WSIB decides case-by-case.
If WSIB refuses the extension, you can appeal to an Appeals Resolution Officer, then to WSIAT. The Office of the Worker Adviser (1-800-435-8980) provides free help for non-unionized workers; IAVGO and the Workers’ Health & Safety Legal Clinic also assist injured workers.
What If Your Claim Is Approved — What Happens Next
Approval letters outline your specific benefits, which typically include:
- Wage replacement (usually 85% of pre-injury earnings, up to an insurable maximum)
- Therapy coverage — through the Community Mental Health Program or approved private clinicians
- Medication coverage for work-related conditions
- Return-to-work support — collaboration between you, your therapist, employer, and WSIB
Therapy is typically delivered in blocks of six sessions under the Community Mental Health Program. Most people are approved for multiple blocks. Our article on virtual WSIB therapy in Ontario walks through what actually happens in a typical session and what the first treatment block looks like.
How to Start Therapy While Your Claim Is Being Processed
You don’t have to wait for claim approval to start therapy. Many people shouldn’t wait — treating the mental health injury early usually leads to better outcomes regardless of how long WSIB takes to adjudicate.
Our team at Aref Psychotherapy offers:
- Free 15-minute consultations — no pressure, no commitment
- Virtual therapy across Canada in 14+ languages
- Trauma-informed care with evidence-based modalities (EMDR, CBT, ACT)
- Registered Psychotherapists experienced with WSIB claims
- Coordination with your WSIB Case Manager once your claim is approved
Starting before approval means you can either pay privately (often reimbursed retroactively if WSIB approves) or use existing benefits coverage. Either way, you stop losing time.
Key Takeaways
Frequently Asked Questions
What's the difference between traumatic mental stress and chronic mental stress?
Traumatic mental stress (TMS) is caused by a specific event — like witnessing violence, a serious accident, or an assault at work. Chronic mental stress (CMS) is caused by ongoing stressors over time, most commonly workplace harassment or bullying. TMS claims often move faster through WSIB; CMS claims require more documentation because you need to show the stressor was sustained and the predominant cause.
Can I file a WSIB claim for burnout from a stressful job?
Not usually. WSIB distinguishes between "substantial work-related stressors" and "typical features of normal employment." High workload, tight deadlines, and demanding supervisors generally fall into the second category and aren't covered. For a CMS claim to succeed, the stressor usually needs to rise to the level of harassment, bullying, or exposure to events that go beyond the normal pressures of the job.
Do I need a lawyer to file a WSIB mental stress claim?
Not to file — filing Form 6 is something you can do yourself. But if your claim is denied or becomes complicated, legal help is often worth it. Free resources include the Office of the Worker Adviser (for non-unionized workers), IAVGO, and the Workers' Health & Safety Legal Clinic. Your union, if you have one, is usually your first stop.
Will my employer find out why I'm on leave?
WSIB shares information about your functional abilities (what you can and can't do at work) with your employer — they need this to accommodate return-to-work. But your employer does not receive your therapy content, your diagnosis details, or your session notes. Clinical information stays between you and your healthcare providers.
Can I keep working while my claim is being adjudicated?
Yes, and many people do — especially if their symptoms are manageable with therapy and accommodations. WSIB can approve health care benefits (like therapy coverage) even if you don't miss work. If you do need to take time off, your employer is obligated to accommodate where reasonable, and WSIB wage replacement kicks in once the claim is approved.
This article is for informational purposes only and does not replace professional mental health advice. If you’re in crisis, please contact Canada’s 9-8-8 Suicide Crisis Helpline by calling or texting 9-8-8. For first responder peer support, Boots on the Ground is available 24/7 at 1-833-677-2668.
Reviewed by the clinical team at Aref Psychotherapy — a team of Registered Psychotherapists serving clients across Canada.