The Link between COVID-19 and Depression
There is no doubt that depression was already a worldwide epidemic prior to the onset of COVID-19. It is estimated that 350 million individuals around the globe are affected by depression, contributiung to a leading cause of disability. Millions of cases of COVID-19 have been reported around the world. Early in the course of the pandemic, respiratory disease were of the main focus. In the following months and as more and more literature became available we were made aware of more possible complications including the cardiovascular, neurologic, dermatologic, and mental health realms. A population-based analysis of depressive symptoms in the US found a 3-fold increase in symptoms during the COVID-19 pandemic compared to before. Patients with pre-existing mental and physical health conditions as well as low social support and socioeconomic status may also be at particular risk for pandemic-related depression.
The Role of Inflammation
Early evidence that inflammation could precipitate depressive symptoms was first derived from hepatitis patients. Subsequent research has shown that elevated systemic levels of inflammation may play a substantial role in disease progression in patient's with depression. The prior presence of depression may also confer an increased risk for further immune-mediated depressive symptoms due to the increased vulnerability of inflammatory immune activation after psychosocial stress.
Circumstances Places Upon Us
These times of COVID-19 have been a very stressul period for many of us.
Increased psychological stress has been widely documented in response to COVID-19. Personal diagnosis, coming into close contact, or the diagnosis of a close family member/friend have each been associated with elevated stress as well as with increased symptoms of depression. The political measures taken to reduce the spread of the virus no matter what side of the isle you sit on have also been associated with elevated stress levels. In a survey of American adults without prior history of a mental health condition, 15% reported 2 symptoms of psychological distress for at least 3 days in the past week, most commonly the sense of feeling nervous, anxious, or on edge. These symptoms were associated with social media and internet engagement with COVID-19 content. The widespread food and supply scarcity and instability in the economy have also played a significant risk for elevating our levels of psychological stress. Lastly, COVID-19 related restrictions have sparked concern for decreased physical activity. In a recent survey of American adults, people active prior to COVID-19 restrictions reported a 32% reduction in physical activity. Why these are so important to take into consideration is because elevated psychological stress is proposed to induce elevated inflammatory levels. It is also notable that in this report, decreased levels of physical activity correlated with an increase in depressive symptoms. Multiple mechanisms link the COVID-19 pandemic-related psychological stress with an inflammatory response that could promote a state of depression.
So What Can We Do?
Physical activity has been shown to be an effective therapy for unipolar depression, with a benefit comparable to antidepressants and psychotherapy. Physical activity is thought to positively affect multiple aspects of immune function, including but not limited to suppressing the effects on inflammation. Though exercise by its very nature induces a transient elevation in inflammatory markers it is also accompanied by a decrease in something called TNFα, which displays an overall protective effect on our neurons, leading to a net anti-inflammatory effect. An increased consumption of “comfort foods” has also been reported in response to COVID-19. In this survey they found that unhealthy inflammatory dietary choices were driven in part by a desire to alleviate poor mental health. This now makes for a perpetual cycle of an increased risk for depression due to the link between higher levels of inflammation and mental health disorders as we discussed prior. Promoting dietary patterns rich in whole foods and low in refined carbohydrates, fast foods, sugary beverages, and processed meats have demonstrated a decrease in depressive symptoms as well as in lowering the inflammatory burden. As a whole, data suggest that dietary and lifestyle changes may play a noteworthy component in the management of increased inflammatory and psychological stress levels of COVID-19 ultimately leading to a potential reduction in depressive symptoms.
References
Perlmutter, Austin. “Immunological Interfaces: The COVID-19 Pandemic and Depression.” Frontiers in neurology vol. 12 657004. 23 Apr. 2021, doi:10.3389/fneur.2021.657004