In the case N.L. v. Mathieu, 2025 QCCS 517, the Superior Court dismissed a medical liability lawsuit filed by a teacher against her former family doctor, in which she sought over $1.9 million in damages.
The plaintiff accused her doctor of having inappropriately prescribed medication over several years, without proper follow-up and without informing her of the risks of addiction. The Court concluded that the doctor did not commit civil fault, as his prescriptions were in line with medical practices at the time in Quebec. Additionally, the plaintiff’s ongoing difficulties could not be causally linked to the care she had received.
Facts of the Case
Throughout her childhood and young adulthood, the plaintiff faced multiple challenges, which ultimately led to significant psychological issues.
It was in this context that the plaintiff first consulted the defendant in November 2006. At that time, she was suffering from anxiety, insomnia, and chronic physical ailments. She had previously consulted other doctors and had been prescribed various medications, including antidepressants and benzodiazepines. After this first consultation, the defendant diagnosed her with anxiety-depressive syndrome and an adjustment disorder. He prescribed a work stoppage and new medication, which was adjusted as the plaintiff’s situation persisted.
Over the years, the plaintiff frequently moved and consulted other doctors, who continued to prescribe benzodiazepines or equivalents. Despite recommendations from these doctors, the plaintiff was reluctant to undergo psychotherapy and repeatedly refused to take antidepressants on a long-term basis.
The plaintiff continued to consult the defendant during her periodic returns to Quebec, with the last consultation being on March 26, 2013.
In 2014, the plaintiff was hospitalized in Alberta following a suicide attempt. Medical notes from this time revealed several stressors, including isolation, unstable employment, family conflicts, and troubled emotional relationships.
In the following years, several doctors and psychiatrists noted that the plaintiff exhibited traits of borderline personality disorder, chronic anxiety, and a difficulty following recommended treatments.
In 2017, the plaintiff filed a lawsuit against Dr. Mathieu, accusing him of having initiated and maintained a medication dependency without adequately informing her of the risks and without ensuring a safe withdrawal process.
Court’s Analysis
The Court began by reiterating that in medical liability cases, the plaintiff bears the burden of proving, on the balance of probabilities, the existence of a fault, damage, and a causal link between them. Specifically, to determine whether the defendant doctor committed a fault, the Court emphasized that the physician has an obligation of means (as opposed to a strict obligation of result) toward their patients. The Court clarified that a disciplinary fault, such as a breach of the Code of Ethics for doctors, does not necessarily constitute a civil fault under Article 1457 of the Civil Code of Québec. It is necessary to assess the breach in context to determine whether the violation directly caused the alleged damage. Furthermore, the doctor’s conduct must be evaluated according to the medical standards of family medicine in Québec at the time of the events, not considering current knowledge.
In this case, the Court concluded that Dr. Mathieu was not at fault in the treatment provided. This conclusion was supported by the lack of sufficient expert evidence from the plaintiff. The Court criticized the choice of experts retained by the plaintiff, noting that most of them were foreign doctors who had never practiced in Québec, and rejected the plaintiff’s argument that the solidarity among Québec doctors (which allegedly led to their reluctance to accept an expert mandate from her) should not penalize her:
[156] The situation that Mrs. L… laments is certainly regrettable, but her observation does not allow her to escape the legal principles and rules of evidence applicable to everyone. Her case cannot be an exception.
As for the duty to inform, the Court explained that it must be evaluated based on what a prudent and diligent doctor of the same specialty would have done under the same circumstances at the same time. Moreover, the obligation to inform a patient about treatment risks is limited to those risks that are reasonably foreseeable and does not extend to exceptional risks.
In this case, the Court noted that, based on the entirety of the evidence, it did not seem that Dr. Mathieu had specifically or explicitly informed the plaintiff about the risks of dependency related to the use of benzodiazepines, nor about the potential consequences of abruptly stopping the medication.
However, the Court emphasized that there must be a causal link between the failure to inform and the damage caused. This link must be analyzed by asking whether, had the plaintiff been informed of the risks, she would have consented to the treatment. The Court acknowledged the possibility that the plaintiff’s testimony could be influenced by the difficulties she had experienced. In this case, the Court concluded that, even if a prudent and diligent doctor at the time would have explicitly mentioned the risk of dependency and the importance of not abruptly discontinuing the medication, Dr. Mathieu’s failure to inform the plaintiff did not directly cause the damage alleged.
Causality and Medical Liability
The Court clarified key principles about causality in medical liability:
[214] The mere possibility of a causal link and the mere loss of a chance are not compensable under Québec law. The plaintiff must prove that the damage is a direct, logical, and immediate consequence of the fault.”
[215] Therefore, the true cause of the damage, as opposed to mere circumstances or occasions of the damage, must be the one that generates civil liability.”
[216] In medical liability cases, expert evidence is generally required to analyze the causal link between the alleged fault and the damage.”
In this case, the Court emphasized that the plaintiff’s ongoing problems were due to a combination of factors: a heavy family history of mental health issues, past trauma, pre-existing symptoms, cannabis use, refusal of recommended treatments, and repeated professional and relational stressors. The expert reports presented by the plaintiff concerning the causal link between her symptoms and the use/discontinuation of benzodiazepines did not seem to account for these factors, some of which were present years before the plaintiff’s first visit to Dr. Mathieu.
As a result, the Court concluded that the plaintiff had failed to prove, on the balance of probabilities, that the symptoms she claimed (which persisted more than 10 years after stopping benzodiazepines) were causally linked to the alleged faults of Dr. Mathieu.
Takeaway
This decision underscores the need to evaluate medical liability based on the medical standards in place at the time of the events and the specific circumstances of each patient. It also serves as a reminder that an alleged fault must be causally linked to the damage suffered to establish civil liability.
