What is the test for determining causation in a sexual assault case?

The general test for causation is the “but for” test, which requires a plaintiff to demonstrate that but for the defendant’s wrongdoing he or she would not have suffered from the injury. However, historical sexual assault cases pose particular causation challenges. As Brenner C.J. noted in Blackwater v. Plint, supra, at para. 365: In cases of historical sexual assault, the plaintiff is likely to be claiming for chronic injuries, often psychological in nature. It is not uncommon for the life history of a victim of a historical sexual assault to include numerous stressful, unpleasant experiences unrelated to the sexual assault. Individuals, such as the plaintiffs in these matters, come before the courts with diagnoses of post-traumatic stress disorder, depression, substance abuse and other psychological conditions. Unravelling the question of causation in these cases arising as they do from torts committed so long ago is a daunting task.