VANCOUVER—Agitation and psychotic symptoms at baseline were associated with more rapid progression to severe dementia among patients with incident Alzheimer’s disease, according to a study presented at the 2012 Alzheimer’s Association International Conference. In contrast, patients with incident Alzheimer’s disease and affective symptoms had a slightly increased risk for severe dementia.
When researchers considered the three groups of symptoms together, agitation and psychotic symptoms predicted a faster progression to severe dementia, but affective symptoms did not, according to Martin Steinberg, MD, Assistant Professor of Psychiatry and Behavioral Sciences at Johns Hopkins University in Baltimore.
Dr. Steinberg and colleagues examined data from the population-based Cache Dementia Progression Study to determine whether specific neuropsychiatric symptoms affected the rate of progression of Alzheimer’s disease. A consensus panel diagnosed 335 cases of incident dementia and examined participants every six to 18 months with the Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR), and Neuropsychiatric Inventory.
The mean time between diagnosis and dementia onset among participants was 1.69 years. Researchers used Cox regression models to analyze psychotic symptoms, affective symptoms, agitation, and apathy as predictors of time to severe dementia, which they defined as an MMSE score of 10 or less or a CDR higher than 2. The investigators also tested covariates, including age of dementia onset, gender, the presence or absence of the APOE e4 allele, and education.
Patients with agitation at baseline had a hazard ratio (HR) of 2.88 for more rapid progression to severe dementia, while patients with psychotic symptoms had an HR of 2.21 for this outcome. In comparison, patients with affective symptoms had a 1.56 HR for more rapid progression to severe dementia. Apathy did not affect the rate of progression to severe dementia.
After controlling for covariates, agitation (HR, 2.62) was more likely to predict more rapid progression to severe dementia than psychotic symptoms (HR, 1.96). Affective symptoms, however, did not predict this outcome (HR, 1.21).
“We recommend caution in inferring clinical implications of these findings,” Dr. Steinberg told Neurology Reviews. “It is not known whether treating psychiatric symptoms may slow progression to severe dementia,” he concluded.