Your mood matters: the connection between serotonin and Long COVID

Author: Jasper van den Brink 

Long COVID, a condition where patients experience persistent symptoms after recovering from COVID-19, has baffled scientists. Efforts made to explain its cause have not provided a definitive explanation. However, a recent study offers a promising theory behind the cause of neurological symptoms in Long COVID patients: reduced levels of serotonin.
 

The study reveals that Long COVID patients show significantly lower levels of serotonin in their bloodstream compared to healthy individuals. Serotonin, a hormone with an important role in regulating your mood, cognition, and various brain functions, appears to be a central player in the persistence of neurological issues associated with Long COVID.

To arrive at these findings, the research team compared blood samples from Long COVID patients with healthy control subjects. They measured the levels of various molecules, including serotonin. The results were remarkable: Long COVID patients showed a 34% reduction in serotonin levels compared to their healthy counterparts. Furthermore, the researchers conducted cognitive tests on the Long COVID patients and found that those with lower serotonin levels performed significantly worse. These tests measured various cognitive functions, including attention, memory, and time management.

Nutrients
The researchers suggest that the reduction in serotonin may be caused by the body’s immune response to the virus. When your body fights off a viral infection, it produces type I interferons. These interferons are responsible for regulating the immune response, but are also believed to be able to deplete serotonin levels.  Additionally, the researchers suggest that reduced serotonin may be caused by damage to the cells that produce the majority of circulating serotonin. These cells, which are located in the gut, produce serotonin from a nutrient called tryptophan. Long COVID patients showed lower levels of the tryptophan nutrient which leads to reduced levels of serotonin. 

SSRIs
The study has important implications for the treatment of Long COVID. Currently, there are no specific remedies for Long COVID, and patients often manage their symptoms with painkillers and other medications. However, this new study suggests that drugs that increase serotonin levels, such as selective serotonin reuptake inhibitors (SSRIs), could be effective in treating the neurological symptoms of Long COVID. It is important to note that these findings are preliminary, and while SSRIs offer promise, they should not be viewed as a solution for Long COVID.

In conclusion, this study shines a new light on the complicated nature of Long COVID. It suggests a new pathway that might explain the long-lasting neurological symptoms that come with the disease. The findings may pave the way for new treatments of Long COVID and improve our understanding of the long-term effects.