Although these findings are observational, they could suggest that providing mental health treatment for people with Alzheimer's disease might slow the loss of independence, said senior author Yaakov Stern, PhD, professor of neuropsychology (in neurology, psychiatry, psychology, the Taub Institute for Research on Alzheimer's Disease and the Aging Brain and the Gertrude H. Sergievsky Center) at CUMC.
"This is the first paper to show that declines in function and cognition are inter-related over time, and that the presence of depression is associated with more rapid functional decline," said Dr. Stern, who also directs the Cognitive Neuroscience Division of the Department of Neurology at CUMC.
Because almost half of Alzheimer's patients have depression, the researchers, who were studying the long-term association between cognitive and functional abilities in the disease, also looked at the role of depressive symptoms in disease progression. They reviewed data that tracked changes in cognition, depression, and daily functioning in 517 patients with probable Alzheimer's at NewYork-Presbyterian Hospital/Columbia, Johns Hopkins School of Medicine, Massachusetts General Hospital, and the Hôpital de la Salpêtrière in Paris, France. Patients were assessed prospectively every six months for more than 5.5 years.
"Making a prognosis for Alzheimer's disease is notoriously difficult because patients progress at such different rates," said first author Laura B. Zahodne, PhD, a postdoctoral fellow in the cognitive neuroscience division in the Department of Neurology and the Taub Institute at CUMC. "These results show that not only should we measure patients' memory and thinking abilities, we should also assess their depression, anxiety, and other psychological symptoms that may affect their prognosis."