Most people who suffer from Alzheimer’s disease will experience some behavioral changes, but findings of a new study reveal that depression, sleep problems and anxiety are indicators that can show up before these patients start to have memory loss.
For the new study published in the journal Neurology on Jan. 14, Catherine Roe from the Washington University School of Medicine, together with colleagues, tracked over 2,416 individuals who were at least 50 years old and who did not exhibit cognitive difficulties when they first visited an Alzheimer’s center.
Over a seven-year period, half of the subjects developed cognitive problems that are indicative of dementia while half remained to have normal cognition.
The researchers found that the patients who developed dementia had increased odds of being diagnosed with depression sooner that the patients who did not develop dementia during the study period.
Thirty percent of the patients who developed the degenerative disease had depression during the fourth year of the study while only 15 percent of those who did not have dementia did.
The researchers likewise found that the subjects who went on to have dementia also developed other behavioral changes such as irritability, depression and apathy sooner compared with those who did not develop the disease.
The participants underwent a series of tests that assessed any decline in their memory, thinking and other behavioral and functional skills, and the researchers observed that the symptoms occurred in the three phases.
Depression, sleep problems and irritability started to exhibit first, which were followed by appetite changes, agitation, anxiety and apathy, and finally delusions, hallucinations, mobility disorder as well as impulsive and inappropriate behavior.
Those who were diagnosed with dementia, however, were observed to show these symptoms earlier, suggesting that non-cognitive changes may start before problems with memory start to appear in patients with Alzheimer’s disease. The researchers did admit that further research is still needed.
"We still don't know whether depression is a response to the psychological process of Alzheimer's disease or a result of the same underlying changes in the brain," Roe said.
Keith Fargo from the Alzheimer's Association, however, said that the disease, which often affects older adults, does not only pose thinking and memory problems.
"It's a universally fatal brain disease where you lose the cells in your brain over time and that manifests in many different ways," Fargo said. "One way is through dementia, but it can manifest in other ways such as depression, anxiety or trouble sleeping."
