Following landmark decision, the threshold for proving mental injury is lower and arguably more uncertain.
Saadati v Moorhead, 2017 SCC 28
In this case, the plaintiff was in a motor vehicle collision on July 5, 2005. His vehicle sustained significant damage, but he appeared uninjured. Though he was taken to the hospital for observation, he was discharged. The collision was the second in a series of five motor vehicle collisions the plaintiff was involved in from January 2003 to March 2009. The plaintiff claimed damages for an alleged brain injury.
At trial, the trial judge ruled most of the plaintiff’s expert evidence in support of a brain injury was inadmissible, but nonetheless concluded the testimony of the plaintiff’s family and friends established the plaintiff suffered psychological injuries caused by the accident. These psychological injuries were “observable consequences” and included personality changes, mood swings, irritability, and cognitive difficulties such as slowed speech. The Court of Appeal overturned the trial judge’s decision because the plaintiff’s expert evidence failed to demonstrate a medically recognized psychiatric or psychological injury.
On appeal, the Supreme Court of Canada (“SCC”) addressed the issues of whether the plaintiff’s claim was sufficiently pled to give notice to the defendant and whether evidence of a recognized psychiatric illness is required for compensable mental injury.
Pleading Mental Injury:
Pleadings suggesting mental injury of some kind may be sufficient to claim mental injury particularly where the defendants take no objection to the plaintiff’s oral and written submissions focusing on the plaintiff’s psychological and emotional symptoms and reactions:
 In claims for negligently caused mental injury, it is generally sufficient that the pleadings allege some form of such injury (Odhavji Estate v. Woodhouse, 2003 SCC 69 (CanLII),  3 S.C.R. 263, at para. 74). The appellant’s Statement of Claim alleges various injuries caused by the accident, including:
h) such further and other injuries as may become apparent through medical reports and examinations, details of which shall be provided as they become known;
and the effects or results of the said injuries upon the Plaintiff include headaches, fatigue, dizziness, nausea and sleeplessness.
(R.R., vol. I, at p. 7)
It also claims “general damages for pain and suffering, loss of earning capacity past, present and future, loss of opportunity, loss of enjoyment of life, loss of physical health . . .”
(R.R., vol. I, at p. 7).
 None of these arguments regarding a “psychological”, “emotional” or “psychiatric” reaction elicited an objection from the respondents before the trial judge. And, in my view, the many allegations of such reaction appearing in the appellant’s oral and written closing submissions, combined with the broad heads of damage alleged in the pleadings, provided ample notice to the respondents of the case which they had to answer. I see no breach of procedural fairness here.
Proving Mental Injury:
The SCC unanimously held evidence of a recognized psychiatric illness is not required to prove mental injury, rather the claimant must establish the “requisite degree of disturbance” – a disturbance which is serious and prolonged going beyond ordinary upsets and annoyances. As the Court exclaimed,
 …..mental injury is not proven by the existence of mere psychological upset. While, therefore, tort law protects persons from negligent interference with their mental health, there is no legally cognizable right to happiness. Claimants must, therefore, show much more — that the disturbance suffered by the claimant is “serious and prolonged and rise[s] above the ordinary annoyances, anxieties and fears” that come with living in civil society (Mustapha, at para. 9)…. Ultimately, the claimant’s task in establishing a mental injury is to show the requisite degree of disturbance (although not, as the respondents say, to show its classification as a recognized psychiatric illness).
Although expert evidence is not required by law, it may serve a function in mental injury claims. In acknowledging expert evidence may be of assistance in determining whether mental injury has been proven, the SCC proffered:
 Nor should any of this be taken as suggesting that expert evidence cannot assist in determining whether or not a mental injury has been shown. In assessing whether the claimant has succeeded, it will often be important to consider, for example, how seriously the claimant’s cognitive functions and participation in daily activities were impaired, the length of such impairment and the nature and effect of any treatment (Mulheron, at p. 109). To the extent that claimants do not adduce relevant expert evidence to assist triers of fact in applying these and any other relevant considerations, they run a risk of being found to have fallen short. As Thomas J. observed in van Soest (at para. 103), “[c]ourts can be informed by the expert opinion of modern medical knowledge”, “without needing to address the question whether the mental suffering is a recognisable psychiatric illness or not”. To be clear, however: while relevant expert evidence will often be helpful in determining whether the claimant has proven a mental injury, it is not required as a matter of law. Where a psychiatric diagnosis is unavailable, it remains open to a trier of fact to find on other evidence adduced by the claimant that he or she has proven on a balance of probabilities the occurrence of mental injury. And, of course, it also remains open to the defendant, in rebutting a claim, to call expert evidence establishing that the accident cannot have caused any mental injury, or at least any mental injury known to psychiatry. While, for the reasons I have given, the lack of a diagnosis cannot on its own be dispositive, it is something that the trier of fact can choose to weigh against evidence supporting the existence of a mental injury.
In light of the above, the Court reinstated the trial judge’s decision on the grounds the plaintiff’s symptoms showed a serious and prolonged mental injury:
 I see no legal error in the trial judge’s treatment of the evidence of the appellant’s symptoms as supporting a finding of mental injury. Those symptoms fit well within the Mustapha parameters of mental injury which I have already recounted. While there was no expert testimony associating them with a condition identified in the DSM or ICD, I reiterate that what matters is substance — meaning, those symptoms — and not the label. And, the evidence accepted by the trial judge clearly showed a serious and prolonged disruption that transcended ordinary emotional upset or distress.
Following this landmark decision, the threshold for proving mental injury is lower and arguably more uncertain. Evidence of a recognizable psychiatric illness is no longer required to prove mental injury. Rather the plaintiff must prove a serious and prolonged mental disturbance which goes beyond ordinary upsets and distress. This decision indicates length and severity of impairment of the plaintiff’s cognitive functions and participation in daily activities will often be important considerations; however, it offers little guidance in assessing general damages for mental injury.
Consequently, this decision raises several implications for insurers. Pleadings which allege mental injury or symptoms of mental injury should be approached cautiously and proactively. Any objections to the pleadings should be conducted early on at trial. The plaintiff’s pre and post-incident psychological, physical and social history will become increasingly important in defending mental injury claims. Evidence of the plaintiff’s mental health, daily activities, nature of employment and personal relationships should be obtained in the early stages of litigation. Further, defendants may want to consider tendering expert evidence to rebut the plaintiff’s claim for mental injury.