Noncognitive symptoms occur earlier in individuals with AD

By Will Boggs MD

Noncognitive symptoms -depression, anxiety, hallucinations, and the like - follow similar patterns in the elderly but occur earlier in individuals who go on to develop Alzheimer disease (AD), researchers say.

"I think that these results indicate that the symptoms of early dementia, in addition to problems with memory and thinking, can include such things as depression, lack of energy, and irritability," Dr. Catherine M. Roe, of Washington University School of Medicine, St. Louis, Missouri, told Reuters Health by email. "If someone comes into the office complaining about what seems to be problems with mood or behavior, the clinician may want to explore whether the patient is also starting to have problems with memory and thinking."

Noncognitive symptoms may be common in Alzheimer disease, but the relative time course of behavioral and functional deficits before onset of cognitive impairment has received little attention.

Dr. Roe's team examined the time course of noncognitive symptoms reported on the Functional Activities Questionnaire (FAQ), Geriatric Depression Scale (GDS), and Neuropsychiatric Inventory Questionnaire (NPI-Q) in relation to one another and to the diagnosis of cognitive impairment using data from 1218 participants in the National Alzheimer's Coordinating Center who progressed to Clinical Dementia Rating (CDR)>0 and from 1198 participants who remained CDR 0 throughout an average of ~4 years of follow-up.

The order of symptom occurrence on the NPI-Q was similar for the two groups of participants, but the time to each NPI-Q symptom (except elation/euphoria) was shorter for participants who progressed to CDR>0 than for those who did not.

GDS symptoms were similar for both CDR groups, except that participants who developed CDR>0 reported more memory problems over time, according to the January 14 Neurology online report.

Difficulties with instrumental activities of daily living (IADL) were uncommon in the CDR 0 group but much more likely among those who received at least one CDR>0 rating.

Based on these findings, the researchers propose three phases of progression of noncognitive symptoms on the NPI-Q: first, irritability, depression, and nighttime behavior changes; second, anxiety, appetite changes, agitation, and apathy; and finally, elation, motor disturbances, hallucinations, delusions, and disinhibition.

"Although the order of symptom occurrence is the same, the symptoms occur earlier in people who go on to develop Alzheimer disease," Dr. Roe reiterated.

"Future research must further elucidate the association between noncognitive changes and distinct subtypes of dementia," the researchers conclude. "Furthermore, as the NACC database continues to grow, longer follow-up of these participants will provide additional insight into the noncognitive course of both healthy aging and dementia."

This research was funded by the Longer Life Foundation, the National Institute on Aging, Fred Simmons and Olga Mohan, the Farrell Family Research Fund, and the Charles and Joanne Knight Alzheimer's Research Initiative of the Washington University Knight Alzheimer's Disease Research Center.

SOURCE: http://bit.ly/1xZUwXU

Neurology 2015.

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