Dementia Rates Increased With Serious Mental Illness

MADISON, WI — Because VHA provides a continuum of care over the life course, the healthcare system has need to better understand what effect bipolar disorder and schizophrenia have on veterans’ risk of dementia.

A study published in the journal Psychiatric Services sought to improve service planning, by assessing the incidence of dementia among VHA patients with bipolar disorder or schizophrenia, with adjustment for comorbid medical conditions.¹

William S. Middleton VA Hospital and the University of Wisconsin-Madison researchers and colleagues used data from the VHA Corporate Data Warehouse to identify all veterans who received VHA care in 2004 and 2005 without a dementia diagnosis and who were alive and between ages 18 and 100 as of Jan. 1, 2006. Participants were categorized as having bipolar disorder, schizophrenia or neither condition on the basis of diagnoses in 2004-2005. Among ongoing VHA users, incidence of dementia was assessed for up to 10 years (2006-2015). The cohort included more than 3.6 million patients.

Controlling for baseline comorbid general medical conditions and substance use disorders, researchers determined that the incidence rate ratios (IRRs) for dementia were 2.92 for those with schizophrenia and 2.26 for those with bipolar disorder, compared with VHA patients with neither condition.

“Among veterans receiving VHA care, diagnoses of bipolar disorder and schizophrenia were each associated with increased risk of receiving a new diagnosis of dementia, even when analyses controlled for baseline medical comorbidities,” the authors concluded. “IRRs were elevated for patients with either condition, compared with those with neither condition, and highest for those with schizophrenia. VHA clinicians should evaluate patients for dementia when signs or symptoms of cognitive impairment are present.”

1. Ahearn EP, Szymanski BR, Chen P, Sajatovic M, Katz IR, McCarthy JF. Increased Risk of Dementia Among Veterans With Bipolar Disorder or Schizophrenia Receiving Care in the VA Health System [published online ahead of print, 2020 Jun 10] [published correction appears in Psychiatr Serv. 2020 Aug 1;71(8):879]. Psychiatr Serv. 2020;appips201900325. doi:10.1176/appi.ps.201900325