A new study demonstrates a bidirectional relationship between depression and memory loss. Scientists have long known that mood and memory are connected, but this is the first study, its authors say, that specifically investigates the relationship between the two. The study found that people with greater depressive symptoms experienced accelerated memory loss. The researchers note the reverse was also true: Significant memory loss resulted in a higher level of depressive symptoms. In other words, each condition exacerbated the other. The researchers analyzed 16 years of data from 8,268 participants, each of whom was examined in alternating years from 2002–2003 through 2018–2019. These were community-dwelling English adults aged 50 or older, with a mean age of 64 at the start of the study. Of this cohort, 55% were female. “The novel element of our work is that we established that the relationship between memory decline and depression is bidirectional,” senior investigator Dorina Cadar, PhD, a lecturer in neuro-epidemiology and dementia at Brighton and Sussex Medical School in the United Kingdom, told Medical News Today. The study is published in JAMA Network PsychiatryTrusted Source. How depression and memory loss are linked Viewing the two conditions as two sides of the same coin suggests new hope for those living with depression, memory loss, or both.
David Merrill, MD, PhD, director of the Brain Health Center at the Pacific Neuroscience Institute, CA, not involved in the study, told MNT that prior to this study, researchers had looked at depression and memory loss independently, “trying to parse them apart as though they’re separate.”
But Merrill noted it has long been understood that memory and mood are strongly linked. “If you’re studying memory, you need to control for mood,” Merrill said. “The substrate of the creation of both phenomena is coming out of the same thing,” he added, noting the similarities between depression and dementia.
Merrill said the activity in the prefrontal cortex and hippocampus are similar in both conditions. When there’s a decrease in frontal lobe activityTrusted Source — as is seen with depression — there is a reduced ability to hold things in working memoryTrusted Source
