It may be the case that she got lost and was unable to get back because of her mental illness. But then again it may not be. The article fails to make it clear. Instead, you almost get the sense that the writer is treating her health history like a scarlet letter. It invites us as readers to draw conclusions that we are simply not qualified to draw: do we have access to her current medical profile, are we investigator in the case?
In other words, if the SAR people or the medical people at the hospital said something to the effect of "she was not in a sound state of mental health," then the medical history would be more meaningful. Otherwise what evidence do we have that her mental health played a role? We don't even know what she suffered from, and whether she continues to suffer from it. Imagine someone dies in a car crash, and the news story says, "this person had a history of heart disease." Are we to surmise that this person had a heart attack while driving, subsequently crashing?
Let me clarify: what I object to is the writing of the article, which almost echoes the unenlightened 19th century attitude towards mental illness as some sort of black mark on a person's record. But these days any blogger with a laptop can play journalism, so why should we be surprised?