Evaluation of MicroRNAs and Vitamin B12 Expression in Subjects with Neurologic Symptoms of Depression, Anxiety and Fatigue in Long COVID-19

This study is investigating whether small molecules in the blood called microRNAs and vitamin B12 levels are different in people experiencing depression, anxiety, or fatigue as part of long COVID — symptoms that persist more than 3 months after a COVID-19 infection. **You may be eligible if...** - You have a confirmed previous COVID-19 diagnosis (by PCR or antigen test) - You are experiencing neurological symptoms of depression, anxiety, or fatigue that started after COVID-19 and have persisted for at least 3 months - You have received at least 2 doses of a COVID-19 vaccine, with the last dose given 3 or more months ago **You may NOT be eligible if...** - You are still in the acute phase of COVID-19 infection (within the last 12 weeks) - You had depression, anxiety, or neurological problems before getting COVID-19 - You have not received at least 2 COVID-19 vaccine doses Talk to your doctor to see if this trial is right for you.