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A person with a cold has a harder time concentrating
Last reviewed: 02.07.2025
Depression of the mental and emotional state during acute respiratory viral infections and colds can be caused by chemical signals sent by the immune system to the brain centers.
Everyone knows the unpleasant state of any cold - after all, many are bothered not so much by a cough or a runny nose, but by a sharp decline in activity in the form of apathy, fatigue, and inability to concentrate. Trying to explain such a situation with the phrase "the disease takes away all your strength" is pointless. After all, not only physical abilities are lost: mental activity becomes more difficult, emotions are leveled out, the psyche becomes depressed.
Perhaps the disease has some effect on brain activity? Or is the cause in the activity of the immune system?
Dr. Thomas Blank and his team conducted a series of studies with rodents suffering from a short-term viral infection. Since the scientists wanted to evaluate the behavior and mental characteristics of the mice, a special test was initiated: the sick animals were placed in a container with water, from which it was difficult for them to get out on their own. What were the researchers able to observe?
Healthy rodents continually repeated attempts to escape from the container. But the sick mice quickly gave up the fight and spent their energy only on staying afloat and not drowning.
According to scientists, with the onset of the infectious process, the animals' immunity stimulated the production of beta-interferon, a specific antiviral agent. This substance is capable of binding to cellular receptors that are part of the blood-brain barrier. When these receptors were disabled, the mice became more resistant to the apathetic state associated with the disease.
If we consider the situation at the molecular-cellular level, we can describe it as follows: when the infection was introduced, the immune defense stimulated beta-interferon, which affects the vascular receptors and activates the production of the immunoprotein CXCL10. This protein belongs to the group of cytokines and weakens the properties of the hippocampal nerve cells. However, we must not forget that there are other variants of the immune response, in which interferon with its antiviral properties is not needed - for example, we are talking about an inflammatory process caused by microbes. Apparently, some other mechanisms are triggered here, causing apathy, drowsiness and loss of working capacity.
From an evolutionary point of view, the situation is clear: psychological sluggishness leads to energy savings, because the patient needs energy to fight the disease. However, scientists would like to learn to control the immune signals that provoke the development of "cold depression" - because today people do not need to conserve their energy as much as they did a hundred thousand years ago.
In addition, similar signs of depression are also found in patients suffering from oncopathologies and autoimmune diseases, so solving this problem would help answer other similar questions.
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