Chronic Stress and Depression: What's the Link?

Prolonged stress can ultimately lead to depression. Of course, some people are more resilient than others. However, this particular problem has increased in society today.

Reviewed and approved by the psychologist Valeria Sabater.

Written by Valeria Sabater

Last update: 15 November, 2021

Chronic stress and depression are related. A hormone links the two. It’s a small peptide that causes a whole series of brain changes when you’re suffering from stress. Indeed, with factors of stress being constant worry and a lack of physical and mental rest, you find yourself pushed towards a state of total exhaustion.

Your brain possesses the amazing ability of neuroplasticity. Everything that surrounds you, the way you interpret it, what you feel, and whatever you’re worrying about, sets off a whole cascade of neurochemical alterations in your brain. When you’re stressed, you gradually stop releasing dopamine. This makes you feel really down, unable to focus, and with no energy. Finally, you end up with depression.

Uncontrolled stress can lead to a depressive disorder. Indeed, studies confirm this to be an absolute fact. However, is there a direct relationship between chronic stress and depression? In other words, if you’re suffering from stress now, will you suffer from depression in a few months? Not necessarily.

That’s because some people are more resilient than others. Your genetics, amongst other factors, act as a kind of protective filter. This means that the psychological wear and tear doesn’t get any worse. Nonetheless, it’s worth noting that the World Health Organization (WHO) suggests that almost ten percent of the population gets a depressive disorder due to suffering prior stress.

Chronic stress and depression: enemies of the brain

Michio Kaku, the famous American physicist and science popularizer, states that your brain is the most complex artifact in the whole universe. Indeed, those hundred billion neurons in your brain that are all connected to each other create their own anatomy, based on what you do every day. In fact, everything you do, everything you think, your personal outlook, and your abilities, all go towards shaping your brain in a unique manner.

However, not everything you experience or do always works in your favor. For example, our society has completely normalized stress. Therefore, you tend to suffer it without realizing how it alters the structure of your brain. In fact, studies conducted at Peking University, China, state that chronic stress is one of the brain’s biggest enemies.

When you’re suffering from stress, structures like your hippocampus or prefrontal cortex lose volume. This results in you finding it difficult to make decisions, concentrate, or remember day-to-day stuff. What’s more, there’s a significant relationship between chronic stress and depression.

The center of self

The existence of the center of self in the brain helps in understanding the link between chronic stress and depression. The center of self is a group of neurons located in the medial prefrontal cortex. They’re decisive in identifying the presence of any depressive disorder. It’s known as the center of self precisely because it’s where your mind thinks about itself.

This area of your brain records all your plans, worries, the imprint of what you’ve already done, what you still have to do; everything concerning “you”. When you go through a stressful period, this area’s very active. That’s because you keep worrying and obsessing, thus feeding that anxiety.

If you don’t deal with this stress properly, you’re likely to experience the first symptoms of depression in around three to six months. Indeed, the MRI scans of people with depression show hyperactivity in the medial prefrontal cortex.

Dopamine: the key to chronic stress and depression

The reason for which chronic stress and depression are so closely linked lies in the hormone corticotropin (CRH). The following sequence explains it:

• At times of stress, your brain produces this hormone. It favors the production of dopamine.
• Dopamine reaches the nucleus accumbens. This region mediates your motivational behavior and energy. The kind that lets you achieve your day-to-day goals.
• If your stress continues over a period of time, things change. In fact, dopamine stops being released. Hence, your brain suffers a deficit of this important neurotransmitter. Consequently, you feel moody, negative, and depressed, and lose your motivation.

However, as we pointed out earlier, not everyone who suffers from chronic stress will end up with depression. That’s because certain genetic factors, as well as resilience, prevent this from happening. It’s important to remember that stress does generate organic changes in your body that can harm your health.

Short periods of stress are usually okay. Consequently, it’s best to try to limit it, channel it, and use it to your advantage. Because you certainly don’t want it to take over and lead to a state of depression.