From COVID Fog to Inflamed Brain: Understanding the Physiology of Post-COVID Depression

　　The 32-year-old Edwards has been unable to sleep at night for several weeks, and he can’t remember whether he hasn’t had a period for 3 or 4 months after the “COVID pass”. The headaches also tormented her irregularly and endlessly. As a graduate student in clinical mental health counseling, Edwards knew he was struggling with two symptoms, depression and anxiety. “I tried very hard to get out of the depression, but every time I would be pulled back forcibly, and in the back and forth between fleeing and being caught, the situation seemed to be getting worse and worse.” Lindenmoss, 30, has a
　　similar encounter. Overwhelming grief and insomnia caught her off guard in the weeks following her recovery from COVID-19. She always suddenly fell into a trough of mood for no reason, either unable to sleep at night, or having nightmares one after another. Even if she is awake, her brain seems not to be sober at times, and some very dark thoughts may even pop up, “Maybe it will feel better if you hurt your body.”
　　Unlike Edwards, Lindenmers is a “relapse.” As a teenager, she suffered from depression. After recovery, she has a lively and outgoing personality, and is still doing corporate promotion work for a company in New York. But the new crown virus seemed to awaken her body memory and dragged her back into that invisible cage again. She started experiencing “social anxiety” again, dreading seeing friends, staying in bed all day on weekends, avoiding calls and texts. After struggling for half a year, she still chose to see a psychiatrist, and the doctor diagnosed that she was suffering from depression again.
Depressed Mood Linked to COVID-19

　　Maybe we don’t have the obvious symptoms of depression and anxiety that Edwards and Lindenmers have. But many people feel that even though their bodies are “healthy”, their minds are still troubled by depression, fatigue, apathy, anxiety or other emotional problems. This may manifest as feeling like you’re feeling drained, drained of energy, feeling unmotivated, as if you shed tears more easily, get cranky, or feel sad.
　　what on earth is it? Is there really a direct relationship between COVID-19 infection and emotional depression? Is it because of my poor psychological quality, or is it possible that I am really sick?
　　At present, many domestic and foreign studies have shown that the new crown epidemic and depression are indeed related. A 2021 study in the United States pointed out that more than 50% of American adults reported symptoms of severe depression after being infected with the new crown.
　　A study published in the well-known medical journal “The Lancet” in May 2022 tracked the mental health trajectory of patients with new crowns in six European countries and found that severe cases of new crowns may be accompanied by persistent symptoms of depression and anxiety. In addition, some studies have pointed out that even if it is not a severe case of the new crown, it may also cause the above-mentioned symptoms of depression and anxiety. In June 2023, the results of a survey released by the Japanese National Center for Reproductive Medical Research also showed that as of October 2022, affected by the new crown epidemic, 13% of Japanese adolescents have moderate or higher depression tendencies.
Causes of COVID-19 Depression

　　So, how does the new crown trigger depression? How long does it take to really get rid of the risk of depression after “COVIDkang”?
　　Intuitively, we can easily understand that depression is related to multiple external pressures. Living through a global pandemic is a physical and mental test for everyone. The social isolation caused by the epidemic has brought unprecedented stress, affecting all aspects of life. Fear of infection and even death for oneself and loved ones, various physical discomforts after infection, loneliness and helplessness caused by isolation, and financial worries have all been cited as the main causes of anxiety and depression. Among health workers, fatigue is an important factor in triggering suicidal thoughts.
　　With the gradual weakening or even elimination of external pressure, including the lifting of isolation and control measures, work, life and study return to normal, and physical symptoms subside, why do many people still feel anxious or depressed? Will it still exist for several months, or even longer?
　　A study published in the BMJ in February 2022 helps explain some of these confusions. The study’s sample size was unprecedented, using health information from millions of people in the U.S. Veterans Affairs health system early in the pandemic. The research report pointed out that the new crown virus has affected us physically and mentally for much longer than we thought, and patients with new crowns face higher mental health risks even a year after infection.
　　By comparing the electronic health records of 154,000 COVID-19 patients and 5.8 million uninfected people, the researchers found that a year after COVID-19 patients recovered, they were still more likely to be diagnosed with a mental disorder or develop related symptoms than controls 46% higher. This includes developing symptoms such as depression, suicidal thoughts, anxiety, sleep disturbances, neurocognitive decline, or “brain fog.” Among them, the risk of “brain fog” was 80% higher than that of the control group. It’s worth noting that “brain fog” isn’t a medical term here, it’s used to describe the feeling of sluggish, blurred, and insensitive thinking. It’s like the brain is shrouded in a hazy fog, which will lead to confusion, forgetfulness, inattention, etc. I believe that “COVIDguo” have more or less similar experiences.
Corona depression isn’t just psychological

　　At the same time, the study pointed out that the depression in the epidemic is not only due to the physical pain caused by the disease and the inner loneliness caused by isolation. In fact, the new coronavirus may cause changes in the brain or other body organs, which leads to the occurrence of mental illness symptoms. .
　　In other words, the impact of the new coronavirus on mental health is a real biological phenomenon, and the depression of the new crown is not only due to psychological factors. At present, there are three main theoretical hypotheses in the medical community to explain the mechanism of depression caused by new crown infection.
　　The first, most mainstream hypothesis holds that after a person is infected with the new coronavirus, the brain will activate microglia and induce an inflammatory response. Autopsy histopathological studies have shown that there is a wide range of inflammatory responses in the organs (including the brain) of patients with acute COVID-19, and microglial activation is the most common pathology found in brain autopsies of patients with COVID-19. Microglia are the main players in the inflammatory response of the central nervous system. They can release inflammatory mediators—cytokines and chemokines—to affect the areas of the brain that regulate emotion and mood, leading to mood swings and depressive behaviors. occur.
　　The second hypothesis proposes that the new coronavirus can attack the lining of blood vessels in the brain, thereby disrupting the brain’s blood and oxygen supply, which may disrupt the area that regulates mood. A lack of adequate blood and oxygen supply can negatively affect brain function, which in turn affects the normal regulation of mood.
　　There is also a third hypothesis that the new coronavirus disrupts the diversity and microbial balance of the gut microbiota, which may change the levels of certain neurotransmitters accordingly. Neurotransmitters are chemical messengers that carry nerve signals throughout the body and brain and are involved in the regulation of mood. Thus, the effect of the virus on gut bacteria may have an impact on mood.
　　These theoretical assumptions all help to explain why we are more prone to low mood or emotional instability, and even depression after the “COVID pass”. But further research is still needed to confirm these theoretical assumptions and better understand the specific mechanism of the new coronavirus’s impact on the brain and body.

Eliminate depression discrimination, depression may just be inflammation of the body

　　In fact, discussions about inflammation-induced depression existed before the outbreak of the new crown. It’s just that the new crown epidemic reminds us once again how to treat mental illness correctly and use scientific knowledge to help eliminate depression, shame and discrimination.
　　A 2014 study of 15,000 children in the Bristol region of south-west England found that those who were free of depression before the age of nine but developed mild inflammation were more likely to have it a decade later at age 18. on depression. The findings suggest that inflammation may be a predictor of depression or depressive behavior.
　　In 2019, British psychiatrist Edward Bullmore published a book called The Inflamed Brain. In it, he reveals a causal link between depression and inflammation in the body and brain, and suggests that an activated immune system may be the root cause of mental disorders. Previously, researchers believed that the brain had an impenetrable barrier, the blood-brain barrier. However, Bullmore believes that when inflammation occurs, cytokines can cross the blood-brain barrier and trigger changes within the brain that can lead to depression.
　　Therefore, it is a wrong concept to attribute depression to poor personal psychological endurance or weak personality. Depression is not just a psychological disease, it also has a considerable physiological basis. Depressed patients, like other patients, are physically ill, and the “parts” are broken and need to be repaired. Therefore, we should look at this disease from an ordinary perspective and give patients enough understanding and support.

Post-coronavirus, let’s regain a better mental state

　　We now know that post-COVID depression may not be because we are not strong enough, intolerant, or hypocritical. If after “COVID Kang”, we still continue to feel depressed or have symptoms of depression, we can bravely seek medical help. If it’s not on the level of depression but still has emotional distress, we can help regulate our bodies and minds through diet, exercise, sleep promotion, and socializing. Several studies have shown that a Mediterranean diet rich in fruits and vegetables, fish, whole grains, legumes and olive oil can help reduce the risk of depression. Regular physical activity and exercise can help us relax and promote the synthesis and secretion of endorphins, which can help prevent or reduce symptoms of depression. At the same time, develop good bedtime habits, such as not drinking too much water, coffee or tea before going to bed, not looking at electronic screens, going to bed and getting up at the same time every day, soaking your feet or taking a hot bath before going to bed are also helpful. Helps us sleep better and helps improve mood. We can also communicate more with relatives and friends, share our inner feelings, and get more emotional support.
　　Once diagnosed, there is no need to fear, the current COVID-19 depression is just as treatable as other forms of depression. In addition to the adjustment of daily life, the treatment options mainly include psychotherapy and drug therapy. Psychotherapy can help patients change negative thinking patterns, improve emotional regulation, and enhance resilience to stress. Drug therapy can relieve symptoms by adjusting the levels of neurotransmitters in the brain. Both Edwards and Lindenmers have successfully emerged from the new crown depression by taking antidepressants and receiving psychotherapy.
　　In addition, a new study published in March 2023 in the British Medical Journal suggests that the situation may not be as bad as we thought. Underscoring human resilience, a McGill University-led team has found that the damage to most people’s mental health from COVID-19 may not be as severe as earlier research suggested, based on a review of 137 studies from around the world. Sun Ying, the first author of the paper, said, “This is the most comprehensive study of the psychological impact of the new crown in the world so far. It shows that, in general, people are more resilient than many people think.”
　　Of course, we cannot be too optimistic. The impact of the new coronavirus on human physical and mental health needs to be evaluated and studied in a longer time frame. The global health crisis brought about by the new crown epidemic reminds us to strengthen the attention and investment in people’s health and public health capacity building at the global and national levels. Dr. Tedros Adhanom Ghebreyesus, Director-General of the WHO, pointed out: “The information we now have on the impact of the new crown on global mental health is only the tip of the iceberg. But this has sounded the alarm for all countries, and more must be done in the field of people’s mental health. attention and support.”