Ask an experienced mental health clinician about the disorder, on the other hand, and you will get a much different response. She will sigh deeply and exclaim that of all the psychiatric patients, borderlines are the most difficult, the most dreaded, and the most to be avoided—more than schizophrenics, more than alcoholics, more than any other patient. For more than a decade, BPD has been lurking as a kind of “Third World” of mental illness—indistinct, massive, and vaguely threatening.