DENVER – The presence of depression, apathy, or agitation in patients who have mild cognitive impairment signals an increased risk of progression to dementia within the next several years, according to a large prospective cohort study.
These neuropsychiatric symptoms may provide a clinically useful alternative to the costly brain imaging studies and cerebrospinal fluid (CSF) biomarkers now being developed as predictors of progression from mild cognitive impairment (MCI) to dementia, Dr. Yonas Geda said at the annual meeting of the American Neuropsychiatric Association.
Dr. Yonas Geda
He reported on 275 patients aged 70-89 years with baseline MCI diagnosed using standard published criteria. They were prospectively followed for a median 2.8 years as part of the Mayo Clinic Study of Aging. The participants, roughly equally split between men and women, were independently assessed for progression to dementia by neurologist evaluation, nursing assessment, and psychometric testing using the Neuropsychiatric Inventory Questionnaire. An expert panel evaluated all three data streams in order to diagnose dementia.
At baseline, 49 patients with MCI had apathy and 226 did not. During follow-up, 43% of those with apathy developed dementia, as did 26% of patients with MCI but not apathy. Upon adjustment for age, sex, education, and Charlson Comorbidity Index score, individuals with MCI and apathy were 2.1 times more likely to progress to dementia than were those with MCI and no apathy, reported Dr. Geda of the Mayo Clinic, Rochester, Minn.
Seventy-one patients had MCI and depression at enrollment. They had a 40% rate of progression to dementia during follow-up, compared with 25% in those with MCI but no depression. This translated to an adjusted 1.6-fold increased risk.
Of the 26 participants with MCI and agitation, 54% progressed to dementia, as did 26% of nonagitated patients with MCI, for a 2.7-fold increased risk.
Dr. Geda said he and his coinvestigators had anticipated that comorbid depression would be the biggest driver of progression from MCI to dementia. To their surprise, apathy and agitation turned out to be stronger predictors, although all three neuropsychiatric symptoms were independently associated with significantly increased risk. The higher risk of incident dementia associated with the neuropsychiatric symptoms became apparent early on in the follow-up period.
He declared having no relevant financial disclosures.