Loneliness as a Public Health Crisis: An Analysis of Post-COVID Memory Loss due to Social Isolation

Written by: Saghi Naghizadeh

Edited by: Gabriela Castro, Fernando Aguilar

(Randall, M. et al., 2011)

When the COVID-19 pandemic began, I was right on the cusp of high school, unaware of how deeply those isolated months would shape me. The first two years of high school passed in a fog of Zoom classes, masked conversations, and social distancing. In the years that followed, something quietly shifted. I noticed I was experiencing forgetfulness, both in the short-term and long-term. Studying took more time, tasks that once came naturally started requiring twice the effort, and I found myself grasping for the details that used to stick to me without trying. I have vivid memories from 2019 and before, but the years 2020 to now? They feel compressed, colorless, and almost indistinguishable, blurred together like one long and unmemorable stretch of time.

I blamed it on the lingering brain fog of long COVID. I had developed it after the second time I contracted the virus and knew that the inflammation from the illness could affect neurological function, memory loss included. That explanation made sense by itself, but I started hearing the same things from friends and family who never contracted COVID-19 at all. Many people in the diverse communities I am a part of started describing everything since 2020 as a “blur” and admitted to not having the cognitive sharpness that they used to have prior to the lockdown. These were not isolated comments. They were patterns in teenagers as well as adults in their 20s, 30s, 40s, and even 50s, many of whom should have been in their peak cognitive years. 

The fact that so many people of different age groups began experiencing memory decline after a shared period of intense social isolation points to something deeper, suggesting that memory loss is a neurological consequence of loneliness and being cut off from the rhythms of human connection. This realization led me to explore how our collective post-pandemic memory loss is due to loneliness. In this analysis, I will examine how loneliness, intensified by the COVID-19 pandemic, is not merely an emotional state but a multifaceted public health crisis with profound neurological, psychological, and societal consequences. It is vital to note that addressing it requires both individual strategies to restore cognitive health through neuroplasticity and systemic interventions that strengthen community connections and prevent isolation.

Neurological Effects of Loneliness

Social Isolation and Stress 

The hippocampus is the region of the brain responsible for the storage and retrieval of memories. Cortisol is the primary stress hormone and has many receptors, primarily glucocorticoid receptors (GR), in the hippocampus. In the biological realm, stress is defined by the environmental forces that bring out a response in an organism. Glucocorticoids, a class of corticosteroids (a type of steroid hormone), play a huge role in controlling the intensity levels of stress responses, as they regulate the amount of stress hormones produced (Randall, M. et al., 2011). Different stress responses in humans include fight, flight, freeze, and fawn. Stress is a natural human response; controllable, acute cases of it are necessary for enabling motivation and addressing threats and challenges in life. However, extreme and chronic stress leads to long-term deficits in the hippocampus and the hypothalamus (the main brain structure regulating stress response).

With social isolation comes a lack of meaningful social connections, which is a major psychological stressor. It activates the hypothalamic-pituitary-adrenal axis (HPA axis), a significant communication system involving the hypothalamus, pituitary gland, and adrenal glands. The HPA axis plays a vital role in regulating stress responses, and its continuous activation leads to increased cortisol (Kim, E. et al., 2015). This creates a positive feedback loop in the brain as excessive levels of cortisol damage the hippocampus, further increasing stress levels and thus leading to memory loss and cognitive decline. A positive feedback loop, also known as the vicious cycle of disease, is a biological mechanism where the output reinforces the input, making it more difficult to break out of the cycle (Mitrophanov, A. et al., 2008). Since each loop worsens cognitive function, the initial input (the social isolation) plays a significant role in causing memory loss, and reversing it can be difficult.

Neuroplasticity

We all have heard of muscle memory and the phrase “use it or lose it.” Just like any other skill, memory is gained or lost based on how much it is used on a daily basis. The human brain, specifically the hippocampus, is super active when we engage in conversations and have to emotionally respond to social situations; the brain’s activity levels decrease as the social interactions are reduced. Since the brain networks controlling memory, communication, and empathy are not being activated as often, we start losing those skills over time. This process is referred to as neuroplasticity, the brain’s ability to reorganize itself based on what we do, say, think, hear, experience, etc. (Puderbaugh, M. et al., 2023). This is done through the brain forming and strengthening connections between the neurons that are being used the most. This is why the content that we feed our brains (books, TV shows, music, etc.) keeps returning to us in the form of our behaviors.

During the COVID-19 lockdown, many of us started to unintentionally feed our brains a repetitive diet of scrolling on social media, attending Zoom classes, and talking to the same people everyday. Exposure to in-person conversations and new environments became limited, and as a result, we no longer got to experience the stimulation that would simultaneously activate multiple brain regions, like the hippocampus and the hypothalamus. Being suddenly stripped away from that rich mental input resulted in the weakening of synaptic connections and the removal of unused pathways in the brain and instead the activation of the HPA axis. Overall, our brains started adapting to the constant stress instead of the typical dynamic stimuli. While neuroplasticity occurs at a relatively rapid rate, it still slows down with age and as the neural connections diminish. While it does not completely stop, it may require more specific triggers to engage it (Ivakhnitskaia, E. et al., 2019). This is why even though we are feeding our brains more human connection years after the lockdown, we still do not seem to be able to regain the same memory and mental clarity as the pre-pandemic.

Post-Pandemic Loneliness as a Public Health Crisis

Public Health focuses on prevention at a community level, using education, data, policy, and public reform, while individualized healthcare tends to focus on treatments of one specific case at a time through medical interventions like diagnosis, medication, and surgeries.

Loneliness is a public health issue, as it affects large and diverse populations instead of only some individuals from a niche demographic. While some biological factors like the presence of a rare chronic illness or mental health issue can exacerbate loneliness, the problem mainly stems from social and structural issues, including but not limited to urban design (e.g., the primary presence of walkable streets vs. public transportation vs. personal vehicles), an imbalance between work and personal life caused by unsupportive workplace cultures, and isolated aging infrastructures (nursing homes, senior living, etc.). Even when loneliness appears to stem from the biological factors listed above, it is often the social consequences, such as stigma, exclusion, and a lack of community support and people to relate to, for those individuals, that truly deepens their isolation. 

Shortly after the pandemic, the U.S. Surgeon General declared loneliness and social disconnection as urgent public health concerns, with health risks just as high  as obesity and smoking. It has been shown that chronic loneliness increases the risk of heart disease by 29% and the risk of stroke by 32% (Holt-Lunstad, J., 2023). These issues would be otherwise preventable; that is why loneliness should be viewed through a public health lens, a framework that emphasizes disease prevention by focusing on social determinants of health illustrated in figure 1 (NACCHO Communique, 2023).

Figure 1. Social determinants of health. Note: Identification of social determinants of health has contributed greatly to the understanding that it is almost never one singular focus that causes or resolves a public health issue. Figure adapted from NACCHO Aboriginal Health News Alerts.

Memory loss is only one of the many problematic results of loneliness. The rise of many other preventable health problems due to social isolation, including but not limited to heart disease, stroke, and depression, increases healthcare costs; it would cost significantly less money to prevent such ailments in the first place than to treat them. This puts even more burden on an already broken healthcare system.

The pandemic and the post-pandemic eras have been associated with spikes in Emergency Room visits among adolescents and young adults due to suicidal ideation and even suicide attempts. During 2021, the peak of the pandemic, there was a 43.6% increase in ER visits for suicide attempts and a 120.4% increase in ER visits for eating disorders among 13-17-year-old females (Overhage, L. et al., 2023). Additionally, a New York-based pediatric Psychiatric Emergency Department longitudinal study found that suicidal thoughts, behaviors, and related diagnoses among ages 5-17 increased from 21.2% in 2019 to 26.3% in 2020 and 30.1% in 2021 (Junewicz, A. et al., 2023). Published in the Journal of American Academy of Child and Adolescent Psychiatry, a systematic review involving 51,000 children and adolescents found that even among previously healthy youths, loneliness during the pandemic was consistently associated with increased levels of depression and anxiety, ruling out possible confounding variables and indicating that those spikes in ED visits were direct effects of isolation and not just of already-existing mental health conditions (Wang, J. et al., 2024). 

This example showcases one of the many strains that was put on healthcare workers during this time and does not even scratch  the surface of all the moral injury that healthcare workers had to experience during this era. A meta-analysis involving 4,400 nurses across the U.S. and Canada revealed that the nurse turnover rate intention increased from 33% pre-2020 to 53% post-2020, with the evidence of this being clearly tied to the high workloads, staffing shortages, burnout, and moral distress as a result of the pandemic (Ren, H. et al., 2024). Healthcare worker burnout is not an individual failure but a systemic and public health issue; acknowledging and addressing its complex, multidimensional nature is the way to ensure that it is treated as such. 

While a lot of the pandemic-era social isolation was inevitable and even necessary, like a slow-moving gas leak, the effects of post-pandemic loneliness are subtle but also very devastating over time if the root cause is not addressed and resolved, at least to some extent. From widespread memory loss to a rise in ER visits as well as healthcare worker burnout and high turnover rates, the aftermath of isolation proves that loneliness affects many layers of society, making it a multifaceted issue that is biological, psychological, and social. The biopsychosocial model of health and disease is a holistic approach to understanding wellness from multiple dimensions (Bolton, D. et al., 2019). This model reinforces that loneliness is an urgent public health concern and not just a feeling or emotional state.

Fighting Loneliness and Regaining Memory

While isolation and memory loss are occurring on large scales and can lead to downstream consequences, lowering quality of life and negatively impacting communities and the healthcare system, the good news is that we can use the knowledge shared above to our advantage. While a lot of the damage done during the peak of the pandemic was due to a lack of public knowledge and resources, it is not yet too late to learn from our mistakes and implement effective systems in place to fight the loneliness epidemic and even work towards improving our cognitive skills.

Fighting the Loneliness Epidemic

While loneliness is a public health issue, it does not mean each individual is not able to make a difference in fighting it. The key to fighting the loneliness epidemic is to seek more community. A New York-based community study suggests the importance of having “third places,” places like churches, coffee shops, bars, beauty salons, libraries, recreation centers, etc. (Oldenberg, R., 1989). These are places where community can be found outside of our homes and workplaces, and investing time and collective effort into building connections in these places, like many of us did pre-pandemic, is the key to fighting this public health issue and preventing its devastating results.

Additionally, with the rise of social media, many trends have rapidly entered mainstream culture, particularly among youth, who now have earlier and more frequent access to platforms like Instagram and TikTok. While trends such as the “mysterious,” “nonchalant,” and “protect your peace” aesthetics may seem harmless on the surface, they often lack the context needed to promote genuine emotional well-being and instead further perpetuate emotional detachment and social withdrawal. In the absence of critical guidance, these trends can worsen the post-COVID loneliness epidemic, especially among adolescents. Given that public health should prioritize prevention, it is crucial to implement early interventions aimed at fostering healthy social development in the digital age. The data from a Scottish survey, involving 3,000 adolescents, indicate a strong correlation between higher classmate and teacher support plus more in-person interactions and lower loneliness among students (Zheng, Y. et al., 2022). Parents must take a more active role in monitoring and discussing online content with their children, and schools should prioritize community-building initiatives, designed in a way that encourages students to participate without making them feel embarrassed or stigmatized for seeking social connection.

Regaining memory and cognitive skills

Our brains do not know the difference between a real experience and when we vividly imagine, and they can rewire themselves based on what we tell or show them (Lamb, C., 2022). This is how we can use neuroplasticity to our advantage. Mental rehearsal (the process of repetitively and mentally practicing and experiencing an event without its physical presence), exposure to novel stimuli, and re-engaging in meaningful social and intellectual activities work together to stimulate the brain into rewiring itself. Some examples of what we can do are learning a new instrument, speaking aloud while solving problems or getting chores done, and mentally visualizing our daily tasks. We can accelerate the brain’s capacity to adapt and heal by intentionally creating both internal and external environments that challenge the brain. In addition to being a deeply biological concept, neuroplasticity is a tool for recovery. Just like any other type of healing, this will not be linear, but with consistency, regaining our pre-pandemic memory and cognitive skills is not impossible.

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