Workplace Mental Health in Ontario: What Employers Are Legally Required to Do

A decade ago, workplace mental health was framed mostly as a wellness issue — nice to have, but not a legal obligation. That framing is no longer accurate. In Ontario, employers face hard legal requirements under multiple statutes, and the tribunals that enforce them have made clear that mental health conditions are treated exactly the same as physical disabilities. This guide explains what the law actually requires and where most employers are still falling short.

Why Workplace Mental Health Is Now a Legal Obligation

Mental health is now the leading cause of disability in Canada, surpassing musculoskeletal conditions. According to the Centre for Addiction and Mental Health (CAMH), 1 in 5 Canadians experiences a mental health problem or illness in any given year. In the workplace, that translates to:

• 30% of all short-term and long-term disability claims in Canada are attributed to mental health conditions
• Mental health issues cost the Canadian economy over $50 billion annually
• Average cost per employee per year: approximately $1,500 in lost productivity
• A single short-term disability claim for mental health costs a company an average of $18,000
• 38% of Canadian workers have taken time off work in the last 5 years due to stress, anxiety, depression, or burnout

These are not just wellness statistics. They represent a legal liability landscape that has been actively expanding through OHSA amendments, Human Rights Tribunal decisions, and, since 2025, updated harassment and electronic monitoring requirements.

Ontario’s Three-Layer Legal Framework

Ontario employers do not face a single mental health law — they face three overlapping frameworks that address different aspects of the issue.

What OHSA Requires

The Occupational Health and Safety Act imposes specific, enforceable obligations related to workplace harassment and violence. These directly address psychological safety, even if the word “mental health” does not always appear explicitly in the statute.

Mandatory Written Policies

Every Ontario employer must have:

• A written workplace harassment policy (posted in a conspicuous location)
• A written workplace violence policy (posted in a conspicuous location)
• Both policies must be reviewed annually
• As of 2025 (Bill 190), both policies must now address online and digital workplace interactions, including harassment via email, messaging platforms, and social media used in connection with work

Workplace Violence Risk Assessment

Employers must conduct a risk assessment for workplace violence, document it, and share the results with the Joint Health and Safety Committee (or health and safety representative, if applicable). For retail and public-facing businesses, this includes customer-on-worker violence, which is a recognized OHSA hazard.

Harassment Investigation Requirements

This is where many employers are still non-compliant. Since Bill 132 (2016), OHSA requires:

• All harassment complaints must be investigated, regardless of how minor they seem
• Investigations must be conducted by a person with no conflict of interest (which rules out the harasser’s direct manager, for instance)
• The outcome must be communicated in writing to both the complainant and the respondent
• Confidentiality must be maintained — sharing investigation details beyond those who need to know is a violation

See also: Workplace Harassment Investigation Ontario

OHSA Enforcement and Penalties

Penalties under OHSA are not merely administrative. Corporations can be fined up to $1.5 million per offence. Individual supervisors and directors can be fined up to $100,000. In cases of criminal negligence causing death or serious harm, imprisonment is possible under Bill C-45 (the “Westray Bill” amendments to the Criminal Code).

Mental Health as a Disability Under the Human Rights Code

Under the Ontario Human Rights Code, “disability” includes mental health conditions. This protection extends to:

• Depression (major depressive disorder, persistent depressive disorder)
• Anxiety disorders (generalized anxiety, social anxiety, panic disorder, OCD)
• Post-traumatic stress disorder (PTSD)
• Bipolar disorder
• Schizophrenia and psychotic disorders
• Addictions (alcohol, drugs, gambling — where the addiction is a dependency rather than voluntary misconduct)
• Burnout, when it rises to the level of a recognized medical condition

The protection applies to current conditions, past conditions, and conditions that are perceived to exist. An employer cannot treat an employee differently because they believe the employee has a mental health issue, even if that belief is wrong.

The Duty to Accommodate Mental Health

Once an employee discloses a mental health condition or the employer becomes aware of one, the duty to accommodate is triggered. It does not wait for a formal request.

What Employers Can and Cannot Ask For

What Accommodation Actually Looks Like

Accommodation is individualized — there is no single formula. Common accommodations for mental health conditions include:

• Modified or reduced hours (including phased return after leave)
• Remote work or a quieter workspace
• Adjusted deadlines or workload modifications during acute episodes
• Reassignment to a different role or team (where the existing environment contributes to the condition)
• Adjusted performance expectations during an active accommodation period
• A specific point of contact rather than multiple supervisors
• Approval for flexible scheduling for therapy appointments

Undue Hardship: A High Bar

The only defence to the duty to accommodate is that it would impose undue hardship. Under the Code, undue hardship can only be based on three factors:

1. Cost (and external sources of funding must be considered first)
2. Outside sources of funding available to offset cost
3. Health and safety concerns

Inconvenience, the preferences of co-workers, or disruption to workflow are not undue hardship. The HRTO expects employers to exhaust all reasonable options before concluding that accommodation is impossible.

The Employer’s Proactive Duty to Inquire

Employers cannot wait passively for employees to self-disclose. If an employee’s performance or conduct deteriorates in a way that might suggest an underlying mental health issue, the employer has a proactive duty to inquire — to ask whether there is something the employer should know that might be affecting the employee’s work, and whether any accommodation is needed.

Proceeding directly to performance management or discipline without this inquiry, when a disability may be the underlying cause, is a significant Human Rights risk.

Return to Work After a Mental Health Leave

Returning from a mental health leave is a transition that many employers manage poorly. The most common errors are either rushing the employee back before they are ready or applying a rigid timeline not grounded in the employee’s actual functional capacity.

An effective return-to-work plan for mental health should include:

1. Pre-return planning meeting — held before the first day back, involving the employee, HR, and the direct manager (not just HR)
2. Phased schedule — starting at reduced hours (e.g., 3 days/week) and building gradually, with clear milestones
3. Modified responsibilities — where the nature of the work contributed to the condition, specific tasks may be modified temporarily
4. Regular check-ins — every 1–2 weeks initially, with a formal review at the 30-day mark
5. Confidentiality commitment — co-workers do not need to know the nature of the leave; team communication should be limited to what is necessary
6. Flexibility provision — allowing adjustments to the plan if the employee’s capacity changes

Under section 17 of the Human Rights Code, an employee’s right to return to work exists only if they can perform the essential duties of the position after accommodation. This threshold gives both parties reasonable footing — it is not “must return to full duties immediately” nor “cannot return until 100% recovered.”

The CSA Z1003 Standard

CAN/CSA-Z1003 is the world’s first national standard for psychological health and safety in the workplace. It is voluntary — no Ontario statute mandates compliance — but courts and tribunals increasingly reference it when assessing whether an employer has met their duty of care.

The standard identifies 13 psychosocial factors that influence psychological health at work:

Organizations that proactively address these factors — through management training, workload assessments, anonymous feedback mechanisms, and clear escalation processes — are better positioned both legally and operationally than those that react only when a complaint or disability claim arises.

The Business Case: What Mental Health Issues Cost

Beyond the legal exposure, there is a direct cost-benefit argument for proactive mental health management:

Research consistently shows that every dollar invested in mental health programs returns $1.62 in reduced absenteeism and presenteeism (Deloitte, 2019). Organizations that implement psychological health and safety measures see reduced turnover, fewer harassment claims, and lower disability costs.

Common Employer Mistakes

1. Treating mental health differently than physical health. Legally the standard is the same. If you would readily give someone on medical leave for a back injury modified duties upon return, you must do the same for depression.
2. Demanding a diagnosis. You are entitled to functional information, not a medical label. Requesting a diagnosis violates privacy and can itself constitute a Human Rights violation.
3. Failing to proactively inquire. If performance or conduct deteriorates and a disability may be a contributing factor, the employer must ask. Waiting for the employee to self-disclose is not sufficient.
4. Breaching confidentiality. Disclosing an employee’s mental health situation — even to their team manager or colleagues — without the employee’s consent is itself a form of discrimination.
5. Conflating performance management and accommodation. An employee on a performance improvement plan who subsequently discloses a mental health condition may be entitled to have the PIP paused while accommodation is explored.
6. Setting an arbitrary RTW timeline. Telling an employee on leave “you must return in 3 months or your position will be filled” imposes a timeline not grounded in the employee’s functional capacity. This approach frequently results in HRTO applications.
7. No written OHSA harassment policy — or an outdated one. Since 2025, harassment policies must address digital and online interactions. Operating with a 2018 template is not compliant.
8. Inadequate harassment investigation process. Delegating an investigation to the accused’s direct manager, or failing to communicate findings in writing, creates significant liability.

When to Get HR Support

Mental health accommodation is one of the most sensitive and legally complex areas of employment relations. Most small and mid-sized Ontario employers do not have internal HR capacity to navigate it confidently.

Consider working with an HR consultant or fractional HR professional when:

• An employee discloses a mental health condition and you are unsure how to respond
• You need to update your workplace harassment policy to meet 2025 OHSA requirements
• You are managing a return-to-work after a mental health-related leave
• A performance or conduct issue may be disability-related
• You have received a Human Rights Tribunal application related to mental health accommodation
• You want to conduct a proactive psychological health and safety review using the CSA Z1003 framework

See also: Duty to Accommodate Ontario | Workplace Harassment Investigation Ontario | Ontario Leaves of Absence Guide

Frequently Asked Questions

Is anxiety or depression considered a disability under Ontario law?

Yes. Mental health conditions including anxiety disorders, depression, PTSD, bipolar disorder, OCD, and schizophrenia are all protected disabilities under the Ontario Human Rights Code. The duty to accommodate applies fully.

Can an Ontario employer fire someone for having a mental health condition?

No. Terminating an employee because of a mental health condition is discrimination under the Human Rights Code. The duty to accommodate must be fully explored before any adverse employment action can be taken.

What can an employer ask about an employee’s mental health condition?

Employers can ask about functional limitations and what accommodation is needed to perform essential job duties. They cannot ask for a specific diagnosis, treatment history, medication information, or access to complete medical records.

What does OHSA require for mental health in the workplace?

All Ontario employers must have written workplace harassment and violence policies, review them annually, conduct risk assessments, and investigate all harassment complaints. Since 2025, policies must also address online and digital workplace interactions.

What does a good return-to-work plan look like for a mental health leave?

An effective plan includes a phased return schedule with gradually increasing hours, modified duties where needed, regular check-ins every 1–2 weeks, clear milestones, and a confidentiality commitment. The plan should be developed jointly with the employee before their return date.

Is an EAP enough to satisfy employer obligations?

No. An EAP is valuable but does not substitute for legal obligations. The duty to accommodate under the Human Rights Code and OHSA requirements for harassment policy and investigation exist independently of any wellness program.

Can an employer discipline an employee whose misconduct was caused by a mental health condition?

Not without first exploring whether the misconduct is disability-related and whether accommodation could address it. Disciplining an employee for conduct stemming from an unaccommodated disability may constitute discrimination under the Human Rights Code.

Sources: Ontario Human Rights Code | Occupational Health and Safety Act | CAMH Mental Health Statistics | CSA Z1003 Standard | Ontario.ca — Mental Health in the Workplace | CMHA Ontario