Can Depression Cause Memory Loss?

Memory problems are common in major depressive disorder (MDD). Many studies have investigated the link between depression and memory.

According to 2019 research, depression can affect cognitive function — including working memory and long-term memory — even after you’ve entered remission.

Working memory is the ability to hold and use information for a short period of time, like when we need to remember a phone number or follow simple directions.

A 2014 review reports that, compared with controls, people with depression had lower executive function, memory, and attention. The authors state that these cognitive impairments are “a core feature of depression.”

Symptoms of depression can also affect self-reported memory problems. A 2017 study found that people with more depression symptoms had higher self-reported memory problems compared with people who had fewer symptoms.

And, according to 2015 research, depression can also disrupt your autobiographical memory — the memories that define who you are and your sense of self.

The authors say that depression can lead to a bias toward remembering more negative memories about yourself, while having less ability to recall positive memories.

Depression affects you both mentally and physically. Brain imaging research has even shown that depression can change the structure of your brain.

Some brain regions affected by depression include the:

• prefrontal cortex, which manages executive functioning (reasoning, planning, and decision-making)
• hippocampus, the key memory center
• amygdala, a region that deals with emotion

These brain regions are all linked, so if something affects one of them — such as emotion processing — it could also affect another, such as memory.

These circuits communicate with each other using neurotransmitters, such as dopamine, serotonin, and glutamate. If these chemicals are too low or too high, it can affect how the neurons communicate, which may also affect memory processes.

Depression and the hippocampus

Researchers in 2015 concluded that people with depression had lower hippocampus volume — a key brain area devoted to memory.

They found this effect in people with recurrent depressive episodes, but not first-time episodes. The effect was stronger in people with early onset depression (when you develop depression before age 21).

The researchers also point out that studies have linked depression to changes in the size of your amygdala, a brain region that deals with emotion.

One theory to explain these depression-related cognitive changes is that stress-induced chemical reactions may lead to a loss of neurons — the nerves that carry information in the brain — and suppressed growth of new neurons.

Rumination may be at least partly to blame for memory problems in people with depression.

Rumination — which is very common in both anxiety disorders and depression — is one way we attempt to regulate our emotions by focusing our attention on repetitive negative thoughts.

Some research suggests that excessive rumination is associated with less cognitive control, which is the ability to voluntarily and flexibly regulate one’s thoughts and behavior. Without proper cognitive control, we’re less able to manage our thinking patterns, self-reflection, and impulse control.

Overall, ruminating takes up a lot of brain space, leaving little room for memory tasks and other thought processes.

Many things can cause memory problems other than depression, including sleep deprivation, medications, and typical aging processes.

To get the most appropriate treatment, the first step is to find out the reason behind your memory challenges.

There are a variety of approaches to test for cognitive issues. A typical cognitive exam might include a:

• Account of your medical history: Your doctor will review your medical and psychiatric health history. You might be asked about medical conditions that run in your family and if you’re currently taking any medications.
• Physical exam or diagnostic tests: Your doctor will listen to your heart and lungs, take your blood pressure, and collect any blood or urine samples for lab testing.
• Cognitive test: This test evaluates your memory, thinking, and problem-solving skills. Some cognitive tests are brief, while others are longer and more complex. Some physicians offer computerized cognitive tests.
• Neurological exam: A professional will test your reflexes, speech, eye movement, and coordination. This may also include a brain imaging test.

Your doctor will want to rule out any other causes of cognitive problems.

Many other conditions can affect memory, including:

• age-related memory loss
• medications
• thyroid problems
• alcohol use disorder or other substance use disorder
• vitamin B12 deficiency
• physical trauma to the head or a concussion
• hypothyroidism
• brain diseases such as Parkinson’s disease or multiple sclerosis
• mild cognitive impairment (MCI)
• Alzheimer’s disease or other types of dementia
• a brain tumor or infection
• stroke

Depending on the outcome of your exam, your doctor may refer you to a neurologist or a mental health professional, such as a psychologist, psychiatrist, or therapist.

If you believe your memory problems are linked to your depression, you might find relief by seeking treatment for depression.

Depression is commonly treated with antidepressants, such as selective serotonin reuptake inhibitors (SSRIs). However, studies have conflicting evidence on whether SSRIs improve or reduce cognitive performance, and it may even vary from person to person.

For instance, one person may discover that their memory problems subside when the SSRI relieves their depression symptoms. Another person may find that the medication makes them feel more forgetful.

It’s important to discuss this with your doctor and find out what path is right for you.

There are several other ways to help with depression-related memory problems. These include:

• Exercise: Exercise benefits working memory, attention, and processing speed.
• Nutrition: Research suggests that following a Mediterranean diet lowers rates of cognitive decline. This diet includes plenty of anti-inflammatory vegetables, fruits, fish, nuts, legumes, and olive oil.
• Cognitive training programs: These include cognitive games and exercises, typically performed on a computer.
• Psychotherapy: Research has shown increased brain activity following talk therapy.
• Non-invasive brain stimulation: Transcranial magnetic stimulation (TMS), and theta-burst stimulation (TBS) are all brain stimulation therapies that may help.

If you’re experiencing memory loss, you may benefit from reaching out to a healthcare professional. Together, you can determine whether your memory problems are caused by depression or something else.

You can also begin to work on your memory at home. This might include starting an exercise program or playing some cognitive games on your computer. Simply engaging in crossword puzzles, Sudoku, or other simple games that stimulate your mind may help as well.