Unfortunately, we have not conducted studies in the general population here in Canada. As a result, I cannot draw any comparisons with the Canadian population. These studies were conducted in specific areas, including Edmonton and Winnipeg. I can tell you that in those studies, the rates were relatively lower—around 3% or 4%.
That is an excellent question, and it's extremely complex. Let me try and give you some answers in that regard. In the United States, the prevalence of post-traumatic stress in the general population over the course of a lifetime is also 6.8%. One is tempted to conclude that it is equivalent. However, another study was conducted in 2005. It is an excellent epidemiological study carried out in accordance with accepted practices.
The same thing was done in Europe, but the prevalence over the course of a lifetime was about 2% or 3%. That is quite surprising. There is a great deal of variation from one European country to the next in terms of prevalence. As you can see, this is a complex matter. Epidemiologists who conduct these studies have trouble explaining why there is so much variation from one country to the other on the same continent. They also have trouble comparing these results to those obtained in the United States.
Furthermore, I should also point out that the prevalence of PTSD among military personnel is somewhat underestimated in this study, for methodological reasons.