A new study demonstrates that depression may worsen memory decline, but one condition may also exacerbate the other. 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 full study is published in JAMA Network PsychiatryTrusted Source.
How depression and memory loss are linked: David Merrill, MD, PhD, from the Pacific Neuroscience Institute in CA, emphasized the interconnectedness of depression and memory, mentioned their shared neurological underpinnings. He pointed out that both conditions involve similar brain regions such as the prefrontal cortex and hippocampus, crucial for memory and mood regulation.
Merrill stressed the necessity of considering mood when studying memory due to their intertwined nature. Dorina Cadar, PhD, from Brighton and Sussex Medical School, further explained that depression disrupts neurotransmitter balance, affecting synaptic plasticity essential for learning and memory. She noted that serotonin deficits can impair hippocampal neurogenesis (process of generating new neurons), critical for memory consolidation.
Cadar also highlighted how high cortisol levels in depression can lead to hippocampal atrophy and inflammatory responses detrimental to cognitive function. Additionally, she pointed out that insomnia related to depression can impair memory consolidation during sleep, particularly in older adults.
Is depression a form of dementia? Dementia may cause mood and behavioral changes, while depression may lead to forgetfulness, which may cause some confusion around these two very distinct — albeit related — conditions. Unlike neurodegenerative dementia, which involves the irreversible death of brain cells, “pseudo dementia” stems from depression that causes brain cells to be less active. In depression, less active brain cells could still be reactivated.
In addition to all the physiological factors, when a experiences loss in memory capacity, Cadar noted “this cognitive impairment can lead to increased frustration, stress, and feelings of isolation.”
New future treatments for depression, dementia: The findings of this study, have “significant implications for future treatment approaches for both conditions and highlighting the need for integrated treatment approaches rather than treating them in isolation,” Cadar said.
Treatment might address both conditions simultaneously, and healthcare providers might develop new early screening programs that monitor older people for both mood and memory.
For now, Merrill said it’s imperative for the individual to aim to change one aspect of their mindset, given the nature of depression, if they hope to feel happier and restore memory function. “The problem is depression really robs you of motivation,” he added.
According to Merrill, physical activity may be the best course of treatment for both conditions. Merrill proposed a future therapy that could involve consulting with your doctor and getting a prescription for physical therapy (PT). The value of this plan, Merrill said, goes beyond the body and brain health benefits. (Medical News Today)