Is it necessary for a psychiatric expert to medically diagnose a psychiatric illness in order for me to receive compensation for the psychological impacts a motor vehicle crash has had on me?
Today’s case is a Supreme Court of Canada decision (Saadati v. Moorhead, 2017 SCC 28) that establishes expert medical opinion is not a precondition for proving a compensable mental injury. In the previous trial decision (Saadati v. Moorhead, 2014 BCSC 1365), Justice Funt concluded that the plaintiff had suffered a mental injury despite no physical injuries, and no medical diagnosis or expert opinion suggesting that the plaintiff suffered a psychological injury. Justice Funt’s finding was based entirely on testimony provided by the plaintiff’s friends and family who described the plaintiff as a “changed man”. As a result, the plaintiff was awarded $100,000.00 for the pain and suffering that had arisen from this psychological injury.
The trial decision was appealed and overturned by the BC Court of Appeal (Saadati v. Moorhead, 2015 BCCA 393) on the basis that an expert medical opinion diagnosing a recognized psychiatric illness is a precondition for establishing a compensable mental injury. Without this expert evidence, the BC Court of Appeal decided that a judge cannot conclude that a mental injury has been suffered as, “a judge is not qualified to say what is, or is not, an illness”.
On appeal to the Supreme Court of Canada, it was determined that expert medical evidence is not a precondition to recovery for a mental injury and the trial decision was restored. With that said, the Supreme Court of Canada was careful to point out that although diagnosis of a recognized pyshciatric illness by a medical expert is not mandatory to establish a compensable mental injury, it is still a very useful and persuasive piece of evidence for a court to consider when faced with alleged psychological injuries:
 This Court has, however, never required claimants to show a recognizable psychiatric illness as a precondition to recovery for mental injury. Nor, in my view, would it be desirable for it to do so now. Just as recovery for physical injury is not, as a matter of law, conditioned upon a claimant adducing expert diagnostic evidence in support, recovery for mental injury does not require proof of a recognizable psychiatric illness. This and other mechanisms by which some courts have historically sought to control recovery for mental injury are, in my respectful view, premised upon dubious perceptions of psychiatry and of mental illness in general, which Canadian tort law should repudiate. Further, the elements of the cause of action of negligence, together with the threshold stated by this Court in Mustapha v. Culligan of Canada Ltd., 2008 SCC 27,  2 S.C.R. 114, at para. 9, for proving mental injury, furnish a sufficiently robust array of protections against unworthy claims. I therefore conclude that a finding of legally compensable mental injury need not rest, in whole or in part, on the claimant proving a recognized psychiatric illness. It follows that I would allow the appeal and restore the trial judge’s award.
 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.
 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.