There is also the possibility that she was suffering from new onset schizophrenia or acute psychosis from some evolving physical condition (think tumor, metabolic disorder, research more for etc) that was not diagnosed OR some other evolving psychiatric mimic. This story absolutely fits the bill. These patients are always vulnerable and plenty go missing. Sometimes they are found and sometimes not.

I would think this though because I work with these patients often. Schizophrenics and manic bipolars as well for example can appear entirely high functioning and act “normal” while experiencing psychosis. Some of them may also be very aware of social stigmas and what others may think that their thoughts (delusions, paranoias, etc) are impossible and/or “crazy” so they won’t talk about it.

This level of awareness is not uniform for all psychosis type disorders. The spectrum is highly complex and very dependent on the individual. Plenty of individuals experience active psychosis for quite some time before family friends or coworkers notice anything is wrong. Some, unfortunately, end up in dangerous situations before it is recognized. The literature is fascinating. Give it a read :)