At the moment, the number of people with long COVID is unkown because there is still no effective diagnosis. This is why is very important to analyze the most common symptoms, which are: depression, anxiety and fatigue. This project seeks to analyze some blood components of people with long COVID, such as microRNAs and vitamin B12, in order to identify the body processes that changed after COVID-19 and thereby design better therapies and diagnostic methods focused on each of them.

The hypothesis is that the expression of miR-21, -146a and -155 will be overexpressed as well as there will be a deficiency of vitamin B12 in serum in subjects suffering from long COVID with neurological symptoms of depression, anxiety and fatigue.

Inclusion Criteria:

• Subjects with confirmed diagnosis of COVID-19 by SARS-CoV-2 infection by PCR or antigen testing.
• With presence of neurological symptoms of depression, anxiety and fatigue associated with COVID-19 after three months from the first day of acute infection symptoms.

Exclusion Criteria:

• Subjects who have presented symptoms of acute infection in the last twelve weeks.
• Subjects who present diagnostic premorbid neurological alterations.
• Subjects who do not have at least 2 doses of COVID-19 vaccine, with last application date equal or older than 3 months.

Subjects with symptoms of depression, anxiety and fatigue after having had COVID-19