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How Does Depression Affect the Brain?

Feb 17, 2021

Sometimes, it feels like our emotions come out of nowhere. When you are struggling with depression, emotions might even seem like an outside force you can’t control.

If you’ve ever wondered about the origin of your feelings, you’re in the right place. Science has shown that emotions are the result of brain activity.

Your brain is full of tiny cells called neurons. Neurons are connected through channels known as synapses. Neurons use synapses to send information to other neurons. They send this information using chemicals or electric pulses.

So how does depression affect the brain? It turns out that a person’s brain structure can change as a result of depression.

Scientists think that changes in your brain’s communication network can alter normal thinking patterns. Over time, this can lead to changes in the brain’s structure, strengthening or weakening certain pathways in the neural network.

New brain imaging technology has taught us more about how depression affects the brain. In this article, we will discuss which parts of the brain are affected and how.

Keep reading to learn more about depression and the brain, and to explore the revolutionary treatment options here at Brain Therapy TMS.

How Does Depression Affect the Brain?

The human brain is incredibly complex. Over recent years, imaging technology has allowed scientists to see the brain in greater detail.

Neuroscience still has a long way to go, but new advances have shed light on the purpose of brain regions in the brain. For one, we know that the limbic system supports a variety of functions including mood, emotion, behavior, long-term memory, and sense of smell.

And, science has told us that three parts of the limbic system are affected by depression: the hippocampus, the thalamus, and the amygdala.


Named after the Greek word for seahorse, hippokampos, this seahorse shaped part of the brain is found in the lowest part of the limbic system.

In people with depression, the hippocampus shrinks. An fMRI study on women with a history of depression showed that their hippocampus was, on average, 9% to 13% smaller. It’s believed stress was the key factor in this shrinking, halting the production of new neurons.

Many experts actually believe this is how antidepressants work, by boosting the concentration of neurotransmitters. These neurotransmitters then promote neurogenesis (the strengthening of nerve cell connections), potentially supporting a healthier hippocampus as well as other parts of the brain.

A shrinkage of this part of the brain can also interfere with memory creation, which can have a profound affect on one’s ability to form a stable and realistic self-identity. Because of these distortions, problems with social relationships can arise too. We’ve also seen that patients with advanced Alzheimer’s disease can have abnormal hippocampus function.

The hippocampus also helps us navigate and sense direction. One study showed that the hippocampus of London cab drivers is bigger than normal. This study also shows how brain regions can grow with regular use.


The thalamus is a large structure made of two symmetrical pieces. This structure is critical for relaying information. Most of the sensory information we process goes through the thalamus, playing a role in functions like speech, behaviors, movements, thinking, and learning.

The thalamus absorbs this information and then sends it to the cerebral cortex part of the brain. It’s the starting point for the stress response sending hormones throughout your body that trigger a certain response. When these hormones become too intense, we see issues like high blood pressure, immune suppression, asthma, and possibly depression.

Studies show that a reduction of these hormones is seen to reduce depressive symptoms.

Research suggests that the thalamus also plays a role in sleep and even consciousness.


Amygdala comes from the Latin word for almond because (you guessed it!) it resembles the shape of an almond. You have two amygdalae in your brain.

Scientists believe the amygdala is important for our emotions and behavior. The amygdala processes fear and can trigger a ‘fight-or-flight’ response. It’s associated with emotions like anger, sorrow, pleasure, fear, and even sexual arousal. The amygdala activates when we recall situations associated with emotions.

Imbalance in the amygdala can change your perception of positive memories. A healthy amygdala helps you process your emotions and preserve good and bad memories.

Depression can have a negative impact on these three brain regions. Imbalance in these areas can alter your stress levels, sleep patterns, and memories.

Let’s take a look at these changes in more detail now.

Structural Changes During Depression

Recent studies have analyzed structural changes in the physical makeup of brains with depression. One change these studies detected was the shrinking of the hippocampus in patients who were depressed.

When your hippocampus gets smaller, you might struggle with executive functioning skills. You might also have trouble concentrating or making decisions.

Another study showed that hippocampus damage can affect your imagination, creativity, and social skills. This can have a significant impact on your ability to carry out daily tasks.

Negative impacts on the thalamus can affect higher level functions like talking and learning. Prolonged depression can also impact our sleeping patterns and the ability to process sensory information.

In patients with depression, the amygdala is also affected. Some studies have shown increased activity in the amygdala during depression. This can indicate a high level of anxiety and fear.

The amygdala helps organize your emotional responses to stressful events. When this region is too active, it might be hard to control your emotional response to triggers.

Finally, depression can have a major impact on communication between your nerve cells. Neurons might send too much information. Or they might become oversensitive to all the signals coming in and out.

When the signaling system in your brain goes awry, it can affect your emotional state. Perhaps, the brain is sending fear signals when you’re safe at home. Perhaps certain positive signals aren’t getting picked up as they should.

New technologies bring promise to address these issues. These devices can help restore normal brain communication and function. One promising option in this arena is TMS.

TMS for a Healthy Brain

Here at Brain Therapy TMS, we offer Repetitive Transcranial Magnetic Stimulation (rTMS).

This non-invasive technique sends short magnetic pulses into your brain. The pulses generate a safe electric current inside your brain.

rTMS can help restore function in the hippocampus, thalamus, and amygdala. It targets regions affected by depression to improve communication between your synapses.

Research shows that rTMS can help neurons form new connections. This can help patients recover normal chemical and electrical messaging.

Have you heard the saying that humans are creatures of habit? Well, our brains are no exception! When certain brain processes happen repeatedly over time, they can become the default.

Just like you can create new habits, you can also create new and healthier patterns in your brain. If you struggle with negative thought patterns, rTMS might be the right option for you.

A Community of Care

Struggling with depression can bring up many questions. How does depression affect the brain? What are my treatment options?

At Brain Therapy TMS, our highly trained staff can answer all your questions. We can help develop a unique treatment plan that works for you.

When you join Brain Therapy TMS, you join a community of care. We are dedicated to providing the best possible service for all our clients.

We look forward to hearing from you! Schedule your free consultation now.

Considering TMS Treatment? Schedule a Consultation!

Tired of the results you’re getting from your standard treatment? Transcranial Magnetic Stimulation may be able to increase your chances of long-term remission, reducing your symptoms and allowing you to live a more joyful life.




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