I'll wade into this one.
I think the issue of denial is not at the time we diagnose a person. In most of our experience—and I'm talking as a medical officer right now—once we have diagnosed them, we try to get them access to care. What's reported as denial is people's not coming forth or not being truthful about the symptoms they're experiencing. We can only give the best diagnosis based on the information the individual is willing to share with us. If they are not willing, there are no tests out there...not yet anyway. We don't have those Star Trek things with scanners. I think the denial is in those people who are unwilling to identify those symptoms. But once someone is diagnosed, usually we will get them to care.
Can they refuse? Absolutely. Nobody can be forced into treatment--not in the military, not in Canada anywhere. They can walk away, and that is their right, as an individual, to refuse treatment. It doesn't mean we will recommend them for full employment, depending on the diagnosis.