Understanding the Connection between Depression and Memory Loss Symptoms

Do you often lose track of where you left your keys or your phone? Do you find it difficult to recall what you've just read? Do you occasionally forget to take your medications?

If you have depression and memory loss symptoms, these issues might sound familiar to you. So, how can depression cause memory loss and what can we do about it? The answers lie within the connections and chemistry of our brains.

Persistent stress increases the brain's levels of the hormone cortisol, which, in turn, decreases the level of a chemical messenger called BDNF . This impairs the growth of nerve cells within the hippocampus of the brain.

We rely on the hippocampus for almost everything related to memory, including memory encoding (getting the information into our memory systems), storage, and retrieval. That is why shrinkage in the hippocampus can result in forgetfulness.

If you have depression and memory loss symptoms, you may have noticed problems with both your short-term memory and long-term memory. Occasionally forgetting where you put your phone or whether you turned off a light may not be a big deal, but losing track of where you are in a major work project or finding that you have only vague memories of a vacation you took a few years ago can have a real impact on your ability to accomplish and enjoy important life activities.

Depression also affects the frontal lobe—the part of the brain behind the forehead. Studies of thousands of people with depression have found significantly reduced volume in this region.

The frontal lobe of the brain helps us to pay attention, so if you have depression, you may find that you're easily distracted. Perhaps you cannot concentrate fully during conversations with colleagues. You lose focus while reading a book, or you find it difficult to follow the plot of a TV show. Your friends, family, or co-workers might have even pointed these changes out to you.

The attention issues associated with frontal lobe shrinkage in depression can exacerbate the memory difficulties caused by a smaller hippocampus.

So depression can, in fact, cause memory loss. But fortunately, depression treatments can help reverse these brain changes.

Professor Ian Hickie, lead researcher of the world's biggest depression study on brain volume, has explained that "the hippocampus is unique in its ability to rapidly generate new connections between cells, and what are lost here [in depression] are connections between cells rather than the cells themselves." That means depression treatments can potentially stimulate the growth of new nerve cells and strengthen novel connections between them. Given that repeated episodes of depression increase the risk to the brain, Hickie and other researchers recommend seeking treatment early.

Transcranial Magnetic Stimulation (TMS) is a non-drug, non-invasive treatment option that helps to form new connections between nerve cells in the hippocampus and other brain regions affected by depression. It specifically increases levels of BDNF throughout the brain, thereby stimulating nerve cell growth. Patients whose depression improves with TMS treatment show improved performance on cognitive tests of verbal and visual memory, attention, and processing speed.

TMS is FDA-cleared and covered by most insurance when at least two antidepressant medications haven't been effective.

When undergoing treatment for depression, it can be reassuring to know you'll also be proactively addressing other brain changes that accompany the condition. Treatment that boosts your mood can also boost your memory, empowering you to live your best life and cherish the memories you make along the way.