Employment & Labour

Liability for the tort of intentional infliction of mental suffering

By Mackenzie Irwin

The tort of intentional infliction of mental suffering (IIMS) is not awarded often and requires the plaintiff to meet a very high threshold.

The elements required to establish IIMS were confirmed by the Ontario Court of Appeal in this 2014 case at para 41, and require the plaintiff to prove that:

  • The defendant’s conduct was flagrant and outrageous;
  • The defendant’s conduct was calculated to harm the plaintiff; and
  • The defendant’s conduct caused the plaintiff to suffer a visible and provable illness.

The first and third branches of the test are objective, but the second branch is subjective.

According to the Ontario Court of Appeal, to satisfy the second branch of the test it “must be shown that the defendant desired to produce the kind of harm that was suffered, or knew that it was substantially certain to follow… the extent of the harm need not be anticipated, but the kind of harm must have been intended or known to be substantially certain to follow.” See this 2010 case at para 78.

The Court of Appeal was clear in the 2010 case that a reckless disregard for the harm that was caused does not satisfy the second branch of the test.

Who may be liable for the tort of IIMS?

The tort of IIMS can be appropriately pleaded against an individual defendant personally, and vicariously against an employer for their employee’s tortious conduct.

Liability of individual defendants in their personal capacity

The Ontario Court of Appeal’s decisions in the 2010 case and the 2014 case are examples of where the analysis for the tort of IIMS was applied to the actions of the individual defendants in their personal capacity.

In the 2014 case, the court found the individual defendant personally liable for the tort of IIMS and upheld the jury’s award of $100,000 for this tort. In that case, the plaintiff was subjected to a campaign of persistent verbal abuse at the hand of the individual defendant, in an effort to drive the plaintiff to quit.

In the 2010 case, the plaintiff’s manager, who had a history of aggressive behaviour and verbal abuse, yelled and swore at the plaintiff because she failed to schedule a client meeting. When the plaintiff tried to explain herself to the manager, he pushed her. Shortly after this exchange, the plaintiff received a negative Performance Improvement Plan.

The Ontario Court of Appeal upheld that personal liability for the tort of IIMS is possible; however, the plaintiff failed to establish the desire to produce harm required by the second branch of the test for IIMS.

Employers’ vicarious liability:

Vicarious liability is the legal doctrine that holds third parties legally liable for the actions of others. Employers can be held liable for the unauthorized or intentional wrongs of their employees.

In this case, the Supreme Court of Canada outlined the following two-part approach to determining whether vicarious liability should be imposed:

  1. Are there any precedents that impose vicarious liability in the circumstances presented in the case at issue;
  2. If the wrongful act can be sufficiently connected to the conduct authorized by the employer or principle to justify the imposition of vicarious liability.

The courts have found employers vicariously liable for the tort of IIMS. In the 2014 case, the court found that the company was vicariously liable for the $100,000 tort award against the individual defendant.

More recently, in this 2017 case, the court awarded $100,000 in general damages for the tort of intentional infliction of mental suffering as against the employer and the two individual defendants.


The tort of IIMS, while challenging to establish, has been successfully pleaded against both employees and employers. To date, the highest award for the tort of IIMS is $100,000 in both the 2014 case and the 2017 case. Note that the 2017 case is currently under appeal.

Employers should be alert to the reality that they can be found vicariously liable for the unauthorized, intentional wrongful actions of their employees and must act on allegations of harassment and tortious conduct among their employees.

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