Frontotemporal dementia complicated by comorbid borderline personality disorder: a case report.

Frontotemporal dementia is the fourth most common cause of dementia in the United States and characteristically presents with an early decline in social conduct, impaired regulation of interpersonal conduct, emotional blunting, and general loss of insight, with relative preservation of memory. This a case of frontotemporal dementia in a 46-year-old woman who presented with existing diagnoses of borderline personality disorder and major depressive disorder. She had been repeatedly evaluated for suicidality and mood lability, which led to her most recent hospitalization, the first at our facility. When the individual's outpatient psychiatrist was contacted following admission, the patient's major depressive disorder was considered largely refractory to treatment. It is the opinion of the authors that the patient's history of borderline personality disorder and the fact that frontotemporal dementia is a relatively uncommon condition delayed her accurate diagnosis. This case illustrates the difficulty faced by the clinician in recognizing a relatively uncommon condition, frontotemporal dementia, when a patient presents with psychiatric symptoms.