How Depression Affects The Brain

Affect Of Depression

It is widely known that depression can seriously damage your health. Recent studies have also found that depression does affect the brain.

Specifically, repeated episodes of depression can lead to a reduction in the size of the hippocampus in the brain responsible for controlling emotions and forming memories, which emphasizes the importance of early intervention, especially for adolescents.

Memory is not limited to remembering simple things such as dates and passwords; it also plays an important role in the development and maintenance of self-awareness.

When the hippocampus shrinks, not only the mechanical memory is affected, but also the behaviors related to self-consciousness will also change. Therefore, the shrinkage of the hippocampus is accompanied by the overall loss of emotional and behavioral control functions.

The good news is that this damage is reversible, but to achieve this goal, you must actually take some measures to change your physical condition.

Chronic depression can damage the brain

An international research team analyzed the brain magnetic resonance imaging (MRI) data of nearly 8,930 people around the world and found that those who suffer from repeated episodes of depression also suffer from symptoms of shrinking hippocampus.

Approximately 65% ​​of all subjects suffering from depression are like this. Subjects who had the first episode of depression showed no signs of hippocampal atrophy, which indicated that hippocampal atrophy was caused by repeated episodes of depression.

It has been reported that those subjects with hippocampal atrophy developed depression earlier than other subjects, generally before the age of 21.

Earlier studies have pointed out that the hippocampus of patients with depression will become smaller, but it is not known whether the hippocampus becomes a factor or the result of depression.

What Happens To The Brain During Depression?

1.
The brain structure and function of patients with depression will change.

With the clinical application of brain imaging technology in the past 20 years, doctors and brain scientists can now use powerful MRI machines to observe a person's immediate inner brain activity and brain structure. With the accumulation of brain imaging data in the past 10 years, psychiatrists finally have a more reliable way to interpret abnormal brain activity related to mental illness.

Brain structure of patients with depression

This advanced method allows us to see that when a person concentrates, the prefrontal lobe of the brain becomes more active. The MRI image shows that the prefrontal lobe is brighter than other areas; or when When a person feels fear and anxiety, the amygdala deep in the center of his brain becomes active. From the MRI image, the amygdala area is particularly shiny.

2.
The size of the hippocampus of the brains of people with depression is significantly smaller than that of people without depression.

The hippocampus is the core area of ​​our brain responsible for memory and cognitive functions, as well as some emotional functions. Many neuroscientists believe that the hippocampus and surrounding brain areas are the only areas of the human brain that have nerve regeneration after adulthood. Atrophy in this area usually corresponds to memory decline, cognitive decline, and a depressed emotional state.

 

The size of the hippocampus 

Without timely treatment, the longer the depression lasts, the smaller the size of the hippocampus of the brain. And if depression is treated in time, the size of the hippocampus will be restored.

3.
Functional magnetic resonance studies also found abnormal brain network activity associated with depression.

What is the brain network ? Based on the accumulation of brain imaging research in the past 20 years, brain scientists have discovered that no single brain area can perform any function of the brain.

abnormal brain network activity associated with depression

When the brain is performing tasks, it often needs to call different areas of the brain that are far away, and these brain areas will cooperate in the form of a network. For example, when you concentrate on reading, the attention network in the front of your brain will be activated to keep you focused; and when you are doing nothing and daydreaming, the front, middle and both sides of the brain will be When activated, the network formed by these brain regions is called the default network. The functions involved in this default network are introspection, imagination, daydreaming, and so on.

4.
So what are the abnormal brain networks associated with depression ?

Studies have found that the reward circuits related to emotion regulation, ruminant thinking, loss of interest, and the brain network related to self-awareness are more or less abnormal in the brains of depression patients, corresponding to a specific location, which is depression The activity and connectivity of the amygdala of the brain of patients with disease will increase, the activity of the anterior cingulate gyrus below the knee will increase, and the activity of the insula and dorsal prefrontal lobe will decrease.

However, the changes observed in these brain imaging studies are only the average trend of a large number of patients. If it is specific to each sick individual, the individual differences between patients are actually very large, and may even have nothing to do with the average trend.

5.
The brain function of patients with depression is also different from that of normal people.

Fudan University performed an MRI scan of the brains of more than 1,000 people and found that depression affects the orbitofrontal cortex in the front of the brain, which is responsible for the lack of perception of rewards. Because there is a problem with the activity of the orbital frontal cortex, when depression patients do not get the rewards they expect, they will feel more disappointed than the average person.

 

The orbitofrontal cortex is also connected to the area of ​​the brain responsible for self-feeling. Therefore, when people with depression do not get feedback from the outside world, for example, no one praises themselves, no one asks for their help, or fails to achieve the expected results after working hard. , These people will feel a strong loss of personal value and low self-esteem.

6.
Why do people with depression often feel that their reactions are slower ?

This may be related to the structural changes in their brains. Magnetic resonance studies have found that the brain structure of patients with depression is different from that of ordinary people. The University of Edinburgh in the United Kingdom scanned the brain white matter fibers of more than 3,000 people and found that the integration of the white matter of the brain in patients with depression was lower than that of ordinary people.

The white matter of the brain is a collection of nerve fibers that connect brain neurons to each other. It is the "highway" for transmitting signals between nerve cells in the brain. The reduced integration of white matter in the brain of patients with depression means that the information between different areas of their brains The transmission efficiency becomes lower and the speed becomes slower.

Eating natural foods may be the key to successful treatment of depression

A very important and encouraging news is that the medical community seems to have the fact that food—not just medical interventions in the form of drugs and/or psychotherapy—is very likely to be necessary for us (either individually or collectively). The best hope for a spiritual foothold in order to approach and achieve success in life. In summary, the following seven foods help fight depression:

Eating natural foods helps to reduce depression

1. Oysters , but avoid oysters from contaminated waters

2. Mussels , but make sure they come from uncontaminated waters

3. Seafood , especially wild Alaskan salmon, herring, sardines and anchovies

4. Animal organs , but only grass-fed animals (non-CAFO animals)

5. Green leafy vegetables

6. Chili

7. Cruciferous vegetables

In order to make it easier for people to eat healthy foods without being misled by wrong dietary restrictions, the researchers of this special study referred to another study published in the British Medical Journal in 2016. It solves the food problem that many medical experts still insisted on as "harmful" until recently. Recent research results are subverting old-school claims about saturated fat, cholesterol, and sodium.

In addition, the harm and potential benefits of saturated fat, cholesterol and sodium to physical and mental health are being re-evaluated based on the latest research. According to the latest American dietary guidelines, cholesterol is no longer considered a worrying nutrient.

Exercise can effectively fight depression and help reshape the hippocampus

Exercise can play a role by releasing hormones and neurotransmitters to make the body happy. When we exercise, the body releases endorphins. Some people call these endorphins "happiness hormones." Endorphins can inhibit pain in the body, and at the same time, they can bring a calming effect to the body like morphine. , The body can feel this effect even in low-level exercise.

Exercise can fight depression

In addition, exercise can also release neurotransmitters called endocannabinoids. Endocannabinoids are related to the reward and punishment system of the brain. Exercise will bring a sense of euphoria to the body. This is the so-called "joy of running." ".

As the body ages, our brain capacity will decrease. However, a retrospective analysis of controlled studies found that the hippocampus in the brains of people who did exercise programs such as walking, running, and cycling were compared to people who did not exercise. The body's capacity will increase moderately, and the hippocampus is an important structure in the brain that participates in emotion regulation.