Depression and the development of depression are influenced by the deregulation of certain hormones in the body: namely serotonin, dopamine, noradrenaline, endorphin, and cortisol. The link between depression and mind is thus very strong. A deregulation of these hormones can play a role in the development of depression.

Mind                                                           <=>                                            Body

In the past, people believed that the mind and body could be separated from one another. Our mind was part of the godly and our body was what we had received to survive on Earth. Since then, this vision has long been changed. If you read the main article on depression or some of the sub-articles on depression, it quickly becomes clear that body and mind cannot be considered to be separate from each other.

Depression can, with time, influence physical functions, just like muscle ache, but this can also happen the other way around. An example of this would be a chronic disease and the way in which the chronic disease is handled. This can cause a depression after some time.

Because of the idea that body and mind are connected, we further explain the way in which the hormones above work.

The sleep and feel-good hormone serotonin

Serotonin is mainly responsible for our sleeping pattern and our feelings of happiness. That is why serotonin is also called the 'feel-good' hormone. Serotonin is not only responsible for a happy mood, but it also makes it so that we remember things. A good memory is therefore something which we can thank the hormone serotonin for. Furthermore, serotonin adds to the extent in which we experience contentment.

Except for these psychological symptoms, serotonin also helps with several physical functions, such as a good blood pressure and a good sleeping rhythm. So, if there is a shortage of serotonin, you might experience issues sleeping. This can include both issues falling asleep as well as problems with constantly waking up during the night. People with depression often experience issues with sleeping. Serotonin can also be found in certain types of food. You might know that there are some types of food which make you feel better when you eat them. The most well-known example among these types of food is probably chocolate.

Some situations, however, can lead to a complete or temporary deregulation of serotonin, which can lead to a shortage of serotonin:

  • Constant stress during extended periods of time
  • Pre-menstrual syndrome
  • Depression

The physical symptoms of depression, too, can have to do with this deregulation of serotonin. For example, you might experience binge eating, headaches, or issues with focusing when serotonin is no longer sufficiently produced. Serotonin can thus affect the development of depression quite a lot, as it causes many of the symptoms of depression.

Pain disappears and euphoria appears thanks to the hormone endorphin

Endorphins are the hormones in our body which have a pain killing function. Your body uses these to relax, after we have experienced pain. Furthermore, endorphins will make it so that you experience less pain, so that our body can recover from the pain.

Just like the hormone serotonin, endorphins add to the experiencing of content and euphoric feelings. In certain situations you feel relaxed and euphoric because endorphins suppress the pain which might be present, and work together with other hormones to make use feel good.

Endorphins are also found a lot in situations which our body consider to be pleasant. An example would be an orgasm. During sex, a lot of endorphins are released. This hormone will sent a signal of contentment to our brain. We can also get this reaction by being active ourselves. For example, when we play sports. After a while you will notice that your body and mind consider sports to be rewarding, and you will feel good after you have played sports. Some people then even feel bad after not having done any sports for a few days. This is because of the secretion of endorphins. Endorphins can be released when we play sports, making us feel happy and content. If we then suddenly play less sports or stop completely, our body might need to 'detox' from this healthy secretion of hormones.

Endorphins, just like morphine, can be a little addicting. You can become addicted to the happy feeling which the secretion of endorphins gives you. Because these hormones bring along a feeling of contentment and happiness, it might be so that you experience depressed feelings if the hormone is deregulated.

It can also be so that you experience more pain if you are depressed. This is because the production of the hormone is deregulated, meaning it can no longer effectively combat pain. Your body can than have the feeling that it cannot relax, which in turn can lead to increased depressed feelings.

Reward and stimulation thanks to the hormones dopamine and noradrenaline

From cognitive psychology we have learned that human beings tend to form habits which are rewarded. Here, dopamine and noradrenaline enter the equation. These two hormones will namely help you in learning new behavior and to form such new behaviors into habits.

While these hormones can help you, it can also sometimes be so that these hormones get a mixed-up signal, meaning they do not help to strengthen healthy habits. Your brain namely manages what is rewarding and what is not, so that your body can produce dopamine and noradrenaline for rewarding behavior. However, if you stimulate a bad habit, which seems rewarding to you, noradrenaline and dopamine will have an effect on these too, strengthening these habits. An example would be smoking: smoking is not healthy for the body, yet many people still find it difficult to stop smoking. This is because the consider smoking to be rewarding. If they then want to stop, this does not give them a good feeling, because the body does no longer experience reward.

Dopamine can also be found in drugs and other substances. Addictions are often established because the dopamine in these substances rewards your body for taking the substances. A shortage of dopamine can also stimulate such addiction. You namely start looking for other ways to increase your dopamine levels. Examples of substances which contain dopamine and thus have an addictive quality, are the following:

  • Drugs
  • Alcohol
  • Cigarettes

Except for the rewarding effect of dopamine and noradrenaline, these hormones also help to improve your memory, perform better, and experience happy feelings. You can find several symptoms of depression in this:

  • Memory problems
  • Issues focusing
  • Somber feelings

These depression symptoms are the consequence of an imbalance of dopamine and noradrenaline. Not only can a shortage of these hormones cause such symptoms, but an excess production of the hormones can also negatively affect the brain. Long-term, drugs will cause gaps to fall in your brain, for example, because they break down synapses. Due to overstimulation, these synapses die, so that your memory and inhibition deteriorate.

Dopamine and noradrenaline also affect several bodily functions. If there is a problem with the production of these hormones, you can possibly experience the following symptoms:

  • Heart palpitations
  • Tenseness
  • Anxiety

If you ever have tried drugs yourself or have seen a documentary about drugs, you might recognize some of these symptoms from people with a severe drug problem.

The stress hormone cortisol

Learned helplessness is one of the most important phenomena in depression. In a depression you often feel helpless, because you have the feeling that these is nothing which you can change about a certain situation. Whatever it is that you do, it never is good enough. The situation will never turn out the way that you want it to. After a while, our body starts to respond to this feeling by increasing the production of the stress hormone cortisol in our adrenocortical (Sapolsky, 2001).

The stress hormone cortisol even is found in burnout. Here, too, the production of cortisol lies at the basis of the development of a burnout. In this, depression and burnout are rather similar. Yet, while both problems are affected by a deregulation of the cortisol production, there still are clear important differences between the two illnesses. If you have a burnout, an exhaustion of the cortisol namely occurs. This means that you have excreted very high dosages of cortisol over an extended period of time, and that your body can no longer do so. You will therefore feel weak and exhausted, because your body can no longer handle the 'overdrive'. This means that you have asked too much of your body, meaning your body requires a period of rest. In depression, this goes the opposite way. If you are depressed, your cortisol levels are still too high. Thus, you will constantly feel nervous. This adds to the worrying behavior. Because your body is stuck in overdrive, it finds it difficult to relax. This therefore also goes for worrying thoughts.

At the hand of cortisol production, we can differentiate between 3 stages of depression:

  • Damage to the hippocampus
  • Positive feelings are turned off
  • Negative feelings are turned off

In the beginning, cortisol will influence your hippocampus. This hippocampus is responsible for your focus and is a center where you can retrieve memories. Because certain cells in the hippocampus are much more sensitive to the cortisol than others, these parts will be the first to be turned off, because they go into 'overdrive'. These 25% of the cells in the hippocampus will stop themselves, which causes memory issues as well as concentration issues.

In a later stage, other centers in the brain will also be shut down, because your body detects an 'overdrive'. The next thing which will be shut down, is the left prefrontal cortex. This cortex is responsible for happy, positive feelings. So, if you are happy, this cortex is the one that tells your body that you are happy. After a while, however, this cortex will be shut down, making us feel somber all the time, and preventing us from laughing about fun things.

In the last stage, our right prefrontal cortex will also be attacked by the overproduction of cortisol. This cortex is responsible for the experiencing of negative feelings. Sometimes you hear people with a depression say: 'I do not think about anything anymore', or 'I no longer feel anything'. This is because the right prefrontal cortex is responsible for negative feelings and when it is shut down, you will feel like you have ended up in a state of apathy.

Because we know that learned helplessness is an important phenomenon in depression, healthcare will focus a lot on this. Oftentimes, the mission in treatment of depression is to once again stimulate people to start making their own choices again. Therapy contains techniques to help someone to break out of the vicious cycle of learned helplessness.

Influence of hormones: a depression test?

If you want to know more about which symptoms of depression you already experience so that you can link this to the influence of eventual hormones, you can take our free depression test here!