4 Ways Depression Affects Brain Health

It’s well-known that depression can take a toll on your mental health, but did you know it can affect other aspects of brain health, too?

“People with depression exhibit differences in their brain as revealed through neuroimaging,” says Avigail Lev, PsyD, a clinical psychologist with the Bay Area CBT Center in California. Research shows that, over time, these physical changes in the brain could lead to changes in the way the brain functions.

So, how exactly does depression change the brain? Here are four ways, according to experts.

“Depression can take a toll on your memory, and this isn't just a matter of forgetfulness,” says Brent Nelson, MD, an adult interventional psychiatrist and chief medical information officer at PrairieCare, a division of Newport Healthcare in St. Cloud, Minnesota.

The issue with depression and memory is not so much memory loss but obstacles to storing, consolidating, and retrieving memories, says Dr. Lev.

The connection between memory problems and depression may be related to changes in the brain. The hippocampus, a part of the brain that can be altered by depression, is essential for forming memories, says Dr. Nelson. “Studies have found that the hippocampus can decrease in size and activity in those with long-standing depression,” he says.

Shrinkage of the hippocampus may be related to cortisol, a hormone released by the body in response to stress. “Chronic stress and elevated cortisol levels associated with depression can also contribute to hippocampal changes, resulting in memory effects,” says Nelson.

“There’s good evidence that depression contributes to inflammation, and, in general, depressed people have greater levels of inflammation than nondepressed people,” says James C. Jackson, PsyD, the director of behavioral health at the ICU Recovery Center in Nashville, Tennessee.

“Inflammation is harmful for the brain and likely contributes to adverse effects,” says Dr. Jackson. But how much depression contributes to inflammation versus the other way around is still not known, he adds.

“Executive functions, such as planning, decision-making, and problem-solving, can also be impaired by depression, leading to difficulties in daily life and work,” says Nelson. “This is often due to dysfunction in the prefrontal cortex, a key brain region for executive functions.”

When this happens, people with depression may experience executive dysfunction, meaning a person’s ability to manage their emotions, thoughts, and actions is disrupted. Executive dysfunction can also impact attention and concentration, says Jackson.

Although the effects of depression on processing speed — “the speed at which you respond to questions, the speed at which you engage in conversation, the length of time it takes you to remember someone’s name,” Jackson says — are not often talked about, these effects can have profound daily implications on someone’s life.

In one study, researchers gave neuropsychological tests to 106 people with current major depression, 119 people with remitted major depression (meaning the symptoms have subsided), and 120 controls without major depression. They did this to study how depression affects processing speed, as well as learning and memory.

Among those who have processing speed, attention, and concentration difficulties, the prefrontal cortex tends to show reductions in overall activity as well as reductions in synchronization with other regions, which means different parts of the brain might not be working together on complex tasks, says Nelson.

Researchers don't know yet if the effects of chronic depression on the brain are permanent. But seeking professional treatment for depression — or sticking to your treatment, if you’ve already gotten help — can not only help you feel better emotionally, but it can help improve your brain health and cognitive well-being, too.

“The good news is that treatment can make a significant difference,” says Nelson. “Therapy, especially cognitive behavioral therapy (CBT), helps individuals develop strategies to address rumination and negative thinking patterns.”

• A sad, anxious, or empty mood that won’t go away
• Feeling hopeless
• Feeling irritable, frustrated, or restless
• Losing interest in things you used to enjoy
• Isolating yourself from friends and family
• Having trouble sleeping or sleeping too much
• Eating a lot less or a lot more than usual, leading to unintentional weight gain or loss
• Having trouble remembering things, concentrating, or making decisions
• Feeling aches, pains, digestive issues, or headaches that don’t have another medical explanation
• Losing your desire for sex or intimacy
• Using alcohol or drugs more frequently
• Having suicidal thoughts or behaviors

• Depression is primarily a mood disorder, but over time, it can also affect brain health in general.
• Brain changes as a result of depression can affect memory, processing speed, and concentration.
• Researchers don’t yet know if changes in the brain caused by depression are permanent.
• Seeking help for depression can improve your symptoms and potentially stave off problems with overall brain health.