How Does Depression Affect the Brain?

Published on: 22 Sep 2021
Clinically Reviewed by Cynthia V. Catchings LCSW-S
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Depression can result in negative emotions, overreactions, reduced intellectual abilities, and a general sense of feeling down. These symptoms can range from mild to severe— with suicidal thoughts occurring in the most critical of diagnoses. All of these are just symptoms of depression, however. The underlying issues, and important areas of study regarding this disorder, have more to do with the actual changes depression can cause to the brain. Here, we’ll explore an answer to the question “how does depression affect the brain?”

How Does Your Brain Change From Depression?

What does depression do to the brain? Unfortunately, this question isn’t easily answered, because the effects of depression on the brain can be quite complex. What’s more, they continue to be studied, since we don’t understand everything there is to know about the relationship between our brains and depression. Even though researchers have more to learn about the cause, effect, and correlation between the brain and depression, they have been able to establish a foundational understanding of how depression affects the brain.

In short, depression is broadly associated with brain inflammation. But we don’t yet know if depression causes brain inflammation, or if it’s the opposite — that the inflammation is causing depression.

Researchers have been able to determine that depression directly impacts multiple areas of the brain, most of which are affected by a loss of gray matter volume (GMV). Gray matter is a type of brain material that’s dense with cells and needed for strong brain activity.

Areas of the Brain Affected by Depression

How depression affects the brain is multifaceted, and many areas of the brain may be impacted. Research has lead us to believe that depression affects the following areas of the brain:

  • Hippocampus: The hippocampus, named after the Ancient Greek word for “seahorse” due to its shape, has a role in many brain functions. Some of what it’s responsible for includes: learning, memory storage, emotions, and stress (connecting other parts that process emotions and stress). The hippocampus plays a central role in how we process recollection and long-term memory. For those living with chronic or recurrent depression, studies have shown that the hippocampus shrinks over time. Fortunately, research indicates that this part of the brain can actually be healed and reversed through treatment for depression. 
  • Prefrontal Cortex: The prefrontal cortex is largely responsible for high-level thinking and planning. In some brain images of people who are depressed, they found abnormally low prefrontal cortex. Additionally, depression severity seems to correlate with how far-declined the prefrontal cortex activity actually is. 
  • Thalamus: The thalamus is the part of the brain that gets the most sensory information. It’s involved in many high-level functions such as speech, thought, behavioral reactions, learning, and movement. Because it links sensory input to positive and negative feelings, depression can affect the thalamus, which can get smaller in those diagnosed with depression. 
  • Caudate Nucleus: The caudate nucleus is most associated with movement, but it also has tangential roles in learning, memory, motivation, emotion, and romantic interactions. There is evidence that supports that the caudate nucleus becomes smaller in those who are depressed. 
  • Insula: The insula assists with both basic functions and automatic ones. It can be involved with our feelings of love, pain, cravings, overall emotions, addiction, and more. It sends sensory signals from both within the body as well as from the outside environment. In a nutshell, the insular cortex’s purpose is to link our sensory experiences and emotional responses. It’s also involved with taste and regulates the immune system. Like the prefrontal cortex, thalamus, and caudate nucleus, the insula also appears to be smaller in depressed people. 
  • Amygdala (unclear results): Though results from studies and research are mixed in regards to how depression affects the amygdala, it’s suggested the two are related. The amygdala processes stress and fear.

These all must be addressed when taking a comprehensive approach to answering the question: how does depression affect the brain? When specific areas of the brain aren’t functioning properly, we can see many changes in behaviors and thought processes. Some of the more significant changes which capture what depression feels like include, but are not limited to:

  • Increased anxiety
  • Memory issues
  • Hopelessness
  • Guilt
  • Difficulty thinking clearly
  • Sleep issues
  • Overreacting
  • Having extremely negative emotions
  • Appetite issues
  • Change is speech patterns (talking more slowly)

Are the Changes Permanent?

The long-term answer to how long the brain is affected by major depressive disorder (clinical depression), as well as what type of effects can be expected, is still being studied. But research suggests the effects can be lasting.

Clinical depression at any level might have a significant impact on the brain, but the result of continued or repeated depression can be especially negative. There’s some evidence to suggest that the effects of depression on the brain compound over time, and some of these changes (for example, those to the hippocampus) in people diagnosed with lifelong major depressive disorder might be present even after years of a depressive episode.

Additionally, levels of translocator proteins also increase in people with depression. These brain chemicals are linked to inflammation in the brain, and studies show they can: 

  • Kill or hurt brain cells
  • Prevent new ones from growing
  • Interfere with thinking
  • Accelerate brain aging 

Even if levels return to normal, even temporary periods of reduced new growth and increased aging can still have potential lifelong impacts. One thing is clear: ongoing depression probably does cause significant, long-term changes to our brain. 

Getting Treatment 

Because of the complex and prolonged effects that depression can have on the brain, it’s a mental health condition that should be treated as soon as possible Thankfully, there are several effective treatments to consider if you’re dealing with depression:

  • Antidepressants: Antidepressant medication uses medically formulated chemicals to control stress and emotion hormones. They work by lowering inflammation and promoting the formation of new connections between neurons.
  • Cognitive Behavioral Therapy (CBT): Cognitive Behavioral Therapy promotes neuroplasticity, which improves the brain’s flexibility and ability to create new pathways. This form of talk therapy has been shown to work, in some cases, as well as or even better than medication. Especially for those with a mild-to-moderate form of depression, it can be highly successful. For more severe cases, a combination of CBT and medication like antidepressants have been found to be extremely effective in reducing depressive symptoms while improving the overall quality of life.  
  • Talk Therapy: Talk therapy (also known as psychotherapy) allows psychiatrists and psychologists to help clients process their emotions on a short-term or ongoing basis. It can teach someone how to make changes to their thought patterns and alter some of the negative behaviors, resulting in a reduction in depressive symptoms overall. 
  • Ketamine: Ketamine was originally approved by the FDA as an anesthetic in the early 1970s. More recently it’s been used to treat very severe depression, like the kind that manifests as thoughts of imminent suicide. This medication can only be used short-term, but might have lasting benefits and positive outcomes in treating suicidal thoughts and severe depression.
  • Electroconvulsive Therapy (ECT): Electroconvulsive therapy stimulates the brain and reduces corticotropin-releasing stress hormones (CRHs). ECT has been shown highly effective in relieving major and severe depression. Some studies show that 8 out of 10 people living with severe depression see substantial improvement after ECT treatment.
  • Neurofeedback:  Neurofeedback, also known as EEG or Neurotherapy, has been proven to be a successful treatment for anxiety and depression. It is a research-based intervention that can improve your brain function through brain training exercises that use advanced technology to “balance” the brain and improve the way the mind functions through intensive brain training exercises.

“Talk therapy is beneficial; it gives us the ability to share and let go of the feelings and thoughts that are affecting us. Talking to  a therapist is sometimes easier than sharing our feelings with a friend or relative, since there is no concern of judgement, disclosure, or other negative responses.” 

Talkspace therapist Cynthia Catchings, LCSW-S, CFTP, CLYL, CMHIMP

In addition to these treatment options, a combination of a healthy diet, consistent sleep habits, regular exercise, therapy, and meditation can assist with how to manage depression. They might not address all your answers about what depression does to the brain, but these are practical ways to minimize many of the effects depression can have on your life.

If you’re living with depression, seeking professional treatment is the best thing you can do for yourself. You don’t have to suffer — there is help out there for you. If you’re having thoughts of suicide or need immediate help, you should call 911. You can contact a psychiatrist for assistance with ongoing symptoms. Your psychiatrist can further answer your questions about how depression affects the brain and what type of depression you may be facing. Your mental health care provider will help develop a course of treatment that will get you back to the path of living and enjoying your life.

Sources:

  1. Zhang FF, Peng W, Sweeney JA, Jia ZY, Gong QY. Brain structure alterations in depression: Psychoradiological evidence. CNS Neurosci Ther. 2018;24(11):994-1003. https://doi.org/10.1111/cns.12835. Published 2018. Accessed August 21, 2021.
  1. Pandya M, Altinay M, Malone DA Jr, Anand A. Where in the brain is depression?. Curr Psychiatry Rep. 2012;14(6):634-642. https://doi.org/10.1007/s11920-012-0322-7. Published 2012. Accessed August 21, 2021.
  1. THE BRAIN FROM TOP TO BOTTOM. Thebrain.mcgill.ca. https://thebrain.mcgill.ca/flash/i/i_08/i_08_cr/i_08_cr_dep/i_08_cr_dep.html.. Published 2021. Accessed August 21, 2021.
  1. Does long-term, severe clinical depression affect the brain? Brain and life. https://www.brainandlife.org/articles/does-long-term-severe-clinical-depression-have-neurologic-effects-on/. Published 2011. Accessed August 21, 2021.
  1. Depression and the brain. Queensland Brain institute. https://qbi.uq.edu.au/brain/brain-diseases/depression/depression-and-brain. Published 2021. Accessed August 21, 2021.
  1. What Anxiety And Depression Does To Your Brain. Advantage mental Health Center. https://advantagementalhealthcenter.com/what-anxiety-and-depression-does-to-your-brain/. Published 2020. Accessed August 21, 2021.

Talkspace articles are written by experienced mental health-wellness contributors; they are grounded in scientific research and evidence-based practices. Articles are extensively reviewed by our team of clinical experts (therapists and psychiatrists of various specialties) to ensure content is accurate and on par with current industry standards.

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