Demographic and Symptom Correlates of Initial Idiopathic Psychiatric Diagnosis in Frontotemporal Dementia.

Introduction: This study aims to measure frequency and correlates of initial idiopathic psychiatric diagnosis in a cohort of 147 patients with Frontotemporal Dementia (FTD)-spectrum disorders.

Methods: Participants were evaluated at the National Institutes of Health in Bethesda, Maryland. Initial participant diagnoses were determined by chart review and patient and informant interviews. Logistic regression was used to assess the relationships between diagnosis and age of symptom onset, gender, education, family history of psychiatric illness, and family history of dementia. Additional exploratory analyses investigated patients' first symptom type.

Results: 25% (n=43) of all the patients reviewed were initially misdiagnosed with an idiopathic psychiatric illness, which is less than half the commonly cited 50% rate.³ Depression was the most common misdiagnosis (46.5%). Family history of dementia, family history of mental illness and an exploratory analysis of behavioral first symptoms suggested significant association with a greater likelihood of initial idiopathic psychiatric diagnosis in FTD patients.

Discussion: This data confirms patterns of initial idiopathic psychiatric diagnosis in FTD and elucidates potential factors underlying misdiagnosis. Potential implications for patient outcomes, caregiver burden and healthcare costs are discussed.