How the psyche influences the immune system

Mental problems have an impact on the defense - and vice versa. Because the brain and the immune system are closely related

Conditioning the defense: psyche and immune system are closely linked

© W & B / Veronika Graf

Poison green milk with a strawberry and lavender aroma - sounds like a challenge for the taste buds. On the other hand, it may come as a surprise that the defense also reacts.

Test subjects for a corresponding study included patients who received immunosuppressive agents as a result of a kidney transplant. They swallowed the pills at the same time as the exotic drink.

The result: "The inhibition of the immune system increased again significantly," reports study director Professor Manfred Schedlowski, director of the Institute for Medical Psychology and Behavioral Immunobiology at the University Hospital Essen.

Healthy through the inner attitude?

We also know from other experiments: the green milk is what makes it. But how can that be? How can a drink without medication affect the immune system? The phenomenon is known as the placebo effect.

It is not an active ingredient, but the expectation. The defense is conditioned to the stimulus of the milk. The patient assumes: if I drink this, my defense will react. This effect is mediated via the psyche.

The fact that the immune system and psyche are closely linked is nothing new. To understand this connection, there is a separate branch of research: psychoneuroimmunology. She wants to uncover the mechanisms by which the immune system, nerves and the brain communicate.

Sick from chronic stress

Textbook knowledge now shows that stress has a direct effect on the immune system. "It is activated by acute stress," explains Professor Carsten Watzl from the Leibniz Institute for Labor Research at the Technical University of Dortmund. In primeval times, from which the stress reaction originates, it almost always meant danger to life and limb.

When the pulse rate rose and sweat broke out, the risk of injury was also increased - and with it the risk of pathogens entering. In the event of acute stress, the body still prepares itself for this by powering up the immune system - even if this is no longer beneficial in the case of deadlines instead of saber-toothed tiger attacks.

If the turmoil is not followed by recovery, the effect is reversed. "Chronic stress inhibits our defenses," says Watzl. The causes include the permanently increased level of the stress hormone cortisol and the constant activation of the so-called sympathetic nervous system. It makes the blood pressure rise and the heart beat faster.

Fend off infections with social contacts

Researchers have found that this reduces the number of immune cells that, among other things, prevent an attack on one's own body. So the defense loses its balance.

Other kinds of feelings can apparently also affect the effectiveness of the defense. "If you feel mentally bad for a long time, your immune system also suffers," says Schedlowski. Good social relationships, however, have a positive effect on the defense against infection - although they actually increase the risk of infection.

Professor Manfred Schedlowski examines how the psyche and the immune system are related

© W & B / Dominik Asbach

But the influence also works in the other direction: A permanently active immune system can hit the soul. "It has been known for a long time that people with chronic inflammatory diseases such as rheumatism suffer more often from depression," says Schedlowski. At first it was thought that the cause was the psychological stress caused by the illness.

Inflamed psyche

The rethink began when depression became a side effect of immunotherapies that artificially induce inflammation. Researchers now assume that the cause of mental disorders can also be the permanent inflammation itself, which leads to functional changes in the brain.

This could be good news for those affected. This opens up a new therapeutic approach: Depression would be treated by stopping the inflammation. "We are still at the beginning," said Schedlowski. "But that's where the journey goes."

Less side effects

He himself is also researching to make the findings usable. So, they could help people who are taking immunosuppressive drugs. By conditioning the immune system, the dose could possibly be reduced - and with it the side effects.

In the case of autoimmune diseases, it would also be conceivable to steer the defense in the desired direction. It is also known that the psyche is involved in a violent way in allergy sufferers. For some, the sight of blooming meadows is enough and the nose begins to itch.

Diagnosis of immunodeficiency? You can get help from dsai e.V., the patient organization for congenital immunodeficiencies at 0 80 74/81 64