High Occurrence of Psychiatric Disorders and Suicidal Behavior Across Dementia Subtypes.

OBJECTIVE: To compare occurrence of clinically diagnosed psychiatric disorders and suicidal behavior (mental health disorders) across dementia subtypes in the largest healthcare system in the United States.

METHODS: We aggregated two national databases (Department of Veterans Affairs [VA] National Patient Care Database, National Suicide Prevention Applications Network [SPAN]) and estimated 2-year prevalence of mental health disorders across five dementia subtypes during fiscal years 2012-2013. Using VA healthcare systems throughout the United States, the sample included 56,296 older patients (≥50 years) with Alzheimer's disease (AD; n = 30,578), vascular dementia (VD; n = 17,924), frontotemporal dementia (FTD; n = 1,181), Lewy body dementia (LBD; n = 3,194), and mixed dementia (MD; n = 3,419). Mental health disorders were determined by International Classification of Diseases, Ninth Revision, Clinical Modification codes and the National SPAN.

RESULTS: Roughly 25% of patients had at least one mental health disorder, with 2-year prevalence reaching 30%-45% in FTD, VD, LBD, and MD. Compared with other subtypes, patients with FTD had the highest prevalence of mood (19%), anxiety (20%), and substance use (19%) disorders, as well as suicidal behavior (4%), with nearly 0.5% with a suicidal plan/attempt. Those with VD also showed a high prevalence of these disorders (14%-17%). Although patients with LBD and MD had a slightly lower prevalence of mood and anxiety disorders (12%-15%), they had a much lower prevalence of substance use disorders (9%) and suicidal behavior (2%). Patients with AD had the lowest 2-year prevalence of all mental health disorders (<7%).

CONCLUSION: Occurrence of mental health disorders is high and differs across dementia subtypes, highlighting the importance of reducing the burden of mental health disorders in dementia subtypes.