– “[t]he loss of our mental health is a more fundamental violation of our sense of self than the loss of a finger”
The unanimous decision of the Supreme Court of Canada, released June 2, 2017, confirmed that the law of negligence requires identical treatment of both mental and physical injury claims. There is no obligation for claimants to prove that their mental injury is sufficient to meet the threshold of psychiatric illness. This would be unfair as there is no corresponding requirement with respect to physical injury. Separate rules for cases of mental injury, but not in cases of physical injury, are not required.
In Saadati v. Moorhead, the Plaintiff was a tractor trailer driver who was involved in five motor vehicle collisions. As a result of these collisions, the Plaintiff sustained injury including chronic pain (from the first accident later aggravated by the third accident). The trial judge also confirmed that the second accident caused psychological injuries, argued by the plaintiff as being concussion-like, including personality change and cognitive difficulties. This finding was based upon the evidence of family and friends who confirmed their observations that the plaintiff’s personality and cognitive skills worsened after the second collision. As the mental injuries caused by the second accident was indivisible from the third accident, the trial judge awarded the Plaintiff a joint sum for non-pecuniary damages.
The British Columbia Court of Appeal overturned the trial judge’s decision. They determined that the required expert evidence of a medically recognized psychiatric or psychological injury had not been provided. The evidence of family and friends was not sufficient as there was a requirement for a diagnosis of a specific psychiatric injury.
The Supreme Court Canada disagreed with the British Columbia Court of Appeal, restoring the trial judge’s decision. The Supreme Court confirmed that mental and physical injuries are to be treated identically at tort law. There is no second standard or special evidentiary requirements for mental injuries as compared to physical injuries. There is no need for a diagnosis of specific psychiatric injury to be made.
The Insurance Bureau of Canada intervened in this case to support the requirement of a diagnosis of psychological injury to prevent “indeterminate” liability. The Supreme Court disagreed, instead emphasising the need of tort law to prevent the stigma of mental illness:
It follows that this Court sees the elements of the cause of action of negligence as furnishing principled and sufficient barriers to unmeritorious or trivial claims for negligently caused mental injury. The view that courts should require something more is founded not on legal principle, but on policy — more particularly, on a collection of concerns regarding claims for mental injury (including those advanced in this appeal by the intervener Insurance Bureau of Canada) founded upon dubious perceptions of, and postures towards, psychiatry and mental illness in general: that mental illness is “subjective” or otherwise easily feigned or exaggerated; and that the law should not provide compensation for “trivial matters” but should foster the growth of “tough hides not easily pierced by emotional responses” (A. M. Linden and B. Feldthusen, Canadian Tort Law (10th ed. 2015), at p. 449; R. Mulheron, “Rewriting the Requirement for a ‘Recognized Psychiatric Injury’ in Negligence Claims” (2012), 32 Oxford J. Leg. Stud. 77, at p. 82). The stigma faced by people with mental illness, including that caused by mental injury, is notorious (J. E. Gray, M. Shone and P. F. Liddle, Canadian Mental Health Law and Policy (2nd ed. 2008), at pp. 139 and 300-301), often unjustly and unnecessarily impeding their participation, so far as possible, in civil society. While tort law does not exist to abolish misguided prejudices, it should not seek to perpetuate them.
Recovery for mental injury in negligence law depends upon the claimant satisfying the same criteria that is applicable to any successful action in negligence: that there was a duty of care breached, damage as a result and a legal and factual causal relationship between the breach and the damage. A duty exists at common law to take reasonable care to avoid causing foreseeable mental injury. It is this cause of action that protects the right of each person to be free from negligent actions that can cause mental injury:
… it is implicit in the Court’s decision in Mustapha that Canadian negligence law recognizes that a duty exists at common law to take reasonable care to avoid causing foreseeable mental injury, and that this cause of action protects a right to be free from negligent interference with one’s mental health. That right is grounded in the simple truth that a person’s mental health — like a person’s physical integrity or property, injury to which is also compensable in negligence law — is an essential means by which that person chooses to live life and pursue goals (A. Ripstein, Private Wrongs(2016), at pp. 87 and 252-53). And, where mental injury is negligently inflicted, a person’s autonomy to make those choices is undeniably impaired, sometimes to an even greater degree than the impairment which follows a serious physical injury (Bourhill v. Young,  A.C. 92 (H.L.), at p. 103; Toronto Railway, at p. 276). To put the point more starkly, “[t]he loss of our mental health is a more fundamental violation of our sense of self than the loss of a finger” (Stevens, at p. 55).
While a specific and accurate diagnosis may be important for treatment purposes, a trier of fact adjudicating a claim of mental injury is to remain focused on symptoms and their effects. There is no requirement that the mental injury match a specific diagnostic classification system. The focus is on the level of harm that the claimant’s particular symptoms represent, not the label that could be attached to them. To establish mental injury, the plaintiff must show that the disturbance is serious and prolonged, rising above the ordinary annoyances, anxieties and fears that come with living in civil society. Expert evidence can help in determining on whether or not a mental injury has been shown but a psychiatric diagnosis is not required. It is open for the trier to fact to find, based on the evidence adduced by the plaintiff, that he or she has proven the occurrence of a mental injury based on a balance of probabilities. The defendant can then call expert evidence establishing that the accident could not have caused any mental injury.
This decision is a step in the correct direction to correct the stigma faced by people with mental illness. The mental illness is not “subjective” or otherwise “feigned” or “exaggerated”. Tort law will not continue to operate to perpetuate the stigma and injustices of those living with mental illness.
 Saadati v. Moorhead, 2017 SCC 28
 Saadati v. Moorhead, 2017 SCC 28 at para. 21.
 Saadati v. Moorhead, 2017 SCC 28 at para. 23.