There is no one reason why some people get Alzheimer’s and others do not. Most scientists point to genetics and lifestyle as the main factors, but there are many subcategories within those factors that all play a part in overall risk: education level, sex, obesity, whether or not someone is a smoker or has high blood pressure, and age itself, among others. Some of these, like smoking, can be controlled; others, like genetics, are just the luck of the draw.
And then there’s depression, which a large body of research points to as a risk factor for Alzheimer’s. Older adults with depression have been identified as twice as likely to develop demetia, and 65 percent more likely to develop Alzheimer’s. People cannot control whether or not they’ll get depression, but they can treat it, which a new study says can help prevent how it affects Alzheimer’s risk.
According to a new study from Boston University School of Medicine, getting evaluated and treated for depression can improve or maintain cognitive function in patients with mild cognitive impairment (M.C.I.), which is considered to be the first stage of Alzheimer’s by most researchers. People with M.C.I. can still function in their day-to-day life, but tasks like paying bills or grocery shopping are noticeably harder.
Researchers looked at data from over 6,700 people with an average age of 72. The participants were evaluated at the beginning of the study for cognitive ability, then followed for two to 12 years.
While results showed that people who started as normal were more likely to progress to M.C.I. if they had depression, anxiety or other mood symptoms, one-third of those who had M.C.I. were able to go back to normal cognition, and those who reverted back had a reduction in depressive symptoms.
“The implication is that successfully identifying and providing effective treatment for these neuropsychiatric symptoms, including depression, may potentially improve or maintain cognitive functioning in many older adults,” said corresponding author Robert Stern, Ph.D., professor of neurology, neurosurgery and anatomy and neurobiology at BUSM, and Clinical Core Director of the BU Alzheimer’s Disease Center.
Researchers still don’t know if late-life depression causes dementia or contributes to it, or if it’s the other way around—those who are pre-symptomatic may experience depression as a result of changes in the brain that will lead to dementa.
“There are many possible explanations for these findings and further research is needed to address this important issue,” Stern cautioned.
This study was published in the Journal of Alzheimer’s Disease.