Just seen a comment on a newspaper article that the police should have said early on that Nicola had a mental health problem and left it at that. The poster supposed this would have indicated she was "vulnerable" and "high risk", both of which terms are vague. Also, if they were going to do that, why not just say she had a health issue? "Mental" doesn't need to be mentioned. An illness is an illness is an illness and our brains are part of our physical bodies.
Vagueness aside, what good would their saying that early on in the search have done? Would it have helped find her?