What Happens To The Brain During Depression?

Mental health conditions like depression can change your brain chemistry. If you want to have a better grasp on your mental state and what kind of treatment you need, you must understand how your brain reacts to depression.

In this overview, we cover key health information on the effects of depression on your brain and how these translate to changes in both mental and physical health.

Why Does A Major Depressive Disorder Change Your Brain?

When you suffer from depression, your brain is physically changed. Research by the National Institutes of Health shows that you lose gray matter volume (GMV) when you suffer from depression. This loss is caused by parts of your brain shrinking due to the hormone cortisol impeding the growth of your brain cells.

The more serious depression a person suffers, the more GMV they lose. Since GMV contains most of your neurons or nerve cells, slowed growth means that your cognitive capabilities are at risk of impairment.

Brain Changes On Depression Patients

A depressed person’s brain goes through many changes due to the influx of brain chemicals and loss of matter. In this section, we break down the three major things that happen to a depressed person’s brain.

Shrinkage Of Several Brain Regions

One of the most common changes seen in a depressed patient’s brain is shrinkage, especially in the hippocampus, thalamus, frontal cortex, and prefrontal cortex. How much these brain areas shrink depends on the length and severity of your depression.

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A chemical imbalance caused by the hormone cortisol – a.k.a. the stress hormone – is what triggers this shrinkage. Depression causes the hippocampus to raise its cortisol levels, impeding the development of neurons in your brain. The shrinkage of brain circuits is closely connected to the reduction of the affected part’s function.

While other cerebral areas shrink due to high levels of cortisol, the amygdala enlarges. The amygdala controls emotion, so this may cause issues like sleep disturbances, mood swings, and other hormone-related problems. An enlarged amygdala is also linked to the development of bipolar disorder.

Brain Inflammation

Major depression is linked to cerebral inflammation. While there’s no solid evidence from experts on whether depression causes cerebral inflammation or vice versa, researchers have posited that these two are closely linked. Studies found that people who have suffered depression for over ten years experience 30% more cerebral inflammation compared to those who suffer from a shorter period of depression.

Since cerebral inflammation kills neurons, it can lead to many complications. The death of neurons and neurotransmitters may lead to shrinkage as well as reduce a person’s neuroplasticity – the ability of brains to change as the person ages. Since new neurons and neurotransmitters will have a tougher time growing, this leads to cognitive problems in the affected person.

Restricted Oxygen Intake

Although researchers have yet to prove a conclusive link, major depression may reduce your oxygen intake. The leading theory is that depression induces a change in your breathing patterns, which can lead to oxygen restriction or hypoxia.

Even minor hypoxia can impede your cerebral function. People who suffer from minor hypoxia exhibit poor judgment, a decrease in motor skills, and memory loss. If sustained for long periods, reduced oxygen intake can lead to inflammation and brain cell damage.


The Effects Of Depression-Induced Cerebral Damage

These changes in your cerebral matter can severely affect your mental and physical health. Here are the three most common effects of depression-induced brain damage:

Sleep Disturbances And Emotional Issues

The cortisol influx caused by depression can cause your amygdala to enlarge, increasing its activity. Since it helps control your emotions, damage to your amygdala can throw your emotions off balance. You may experience uncontrollable mood fluctuations as a result, causing you to experience both negative and positive emotions very intensely.

An enlarged amygdala doesn’t just impede your emotional health and your mood stability – its increased activity can also cause other issues, like sleep issues and disturbances. Sleep deprivation, in turn, can worsen your overreactions to stimuli. Poor sleep also causes you to develop a more negative mood and mindset, which can cause your depression to worsen.

Since this creates a feedback loop, issues with your amygdala can be one of the most dangerous things about major depressive disorder.

Lower Cognitive Capabilities

Cerebral damage found in major depressive disorder patients can lead to weaker cognitive functions. Cognitive function loss happens due to the degradation of their neurons.

Increased release of stress hormones is the main cause of this issue. Long-term cortisol hormone exposure causes neuron development to slow or stop, leading to shrinkage.

Hippocampus damage leads to memory problems, trouble with concentration, and executive dysfunction. These depression symptoms are usually worse in people that have been afflicted by degenerative conditions like Alzheimer’s disease and Parkinson’s disease.

Susceptibility To Physical Health Issues And Illness

Stress hormones make your heart beat faster as if you’re constantly in danger. Because your heart isn’t meant to beat at high speeds for extended periods, this could lead to a life-threatening heart illness in the future.

Depression also impacts your digestive system’s health, especially if you binge eat or take antidepressant medications. If you rapidly gain weight during a depressive episode, you’re more likely to develop diseases closely tied to obesity, like diabetes. Conversely, depression may also cause someone to lose their appetite for food and experience rapid weight loss, which can be equally harmful to the body.

Some people may use drugs or alcohol as a way to deal with their symptoms of depression, leading to substance use disorders. In some cases, this substance abuse issue can develop into life-threatening addictions.



Depression alters both your mind and body, and almost always for the worse. The hormones released during episodes of depression can cause cerebral damage, emotional instability, sleep disorders, and impaired cognitive abilities.

Fortunately, you don’t have to deal with mental health issues alone. If you or a loved one is suffering from depression, contact us for more information on how we can help with our depression treatment programs.