Content warning: This article contains mentions of suicide.

Why do you feel lonely? It might be because, at the moment, you can’t see your friends in person. But we also feel lonely even in times when we can meet up with friends. What even is loneliness, and why does it feel like it’s getting worse?

Loneliness is something we’ve all experienced at some point or another. It silently takes over our minds, and makes us feel more tired and depressed, without us realizing that it is the cause of our unhappiness.

All of us, even the least social, will feel lonely at some point, simply because humans are social creatures. We have socialization built into us, and losing that socialization after a certain point becomes as lethal as any physical illness. It can lead to increased risks of heart disease, obesity, and suicide.

Loneliness is described as a disconnect between our perceived and desired levels of social connectedness. It’s what we feel when we don’t have enough friends, or we aren’t able to get the quality time we truly want with them.

An important distinction to make here is that loneliness is different from social isolation. While the definition of loneliness can vary from person to person, social isolation is objective and refers to someone who is physically distanced from society.

Professor Roger McIntyre, a researcher at UHN, pointed out that the subjective experience of loneliness is heightened in the case of celebrities. We hear celebrities and famous or popular individuals talk all the time about feeling lonely, and we wonder how they can be lonely if they’re loved by so many people.

Take Taylor Swift, for example, who is often referred to as “the music industry” by her literal hundreds of millions of fans. Yet, in a documentary about her, Miss Americana, she revealed that she has struggled with loneliness throughout her life — and it especially hits her when she’s in the spotlight.

“Shouldn’t I have someone that I could call right now?”

That is what she said was going through her mind after winning Album of the Year in 2016 — a moment that should have been filled with joy and celebration. And while we’re sure she did celebrate, that quote being her first response goes to show how lonely she felt in the spotlight.

We look at all her fans — all the love and adoration she gets despite the hate that the spotlight brings — and we still can’t comprehend how she must feel lonely. But the issue is that those connections aren’t the proper interpersonal relationships we need. They’re superficial, and not enough to prevent those feelings of loneliness.

Meanwhile, some individuals can be content with just three or four connections, and can feel completely satisfied if those connections are deep enough and maintained properly.

An epidemic of loneliness

Over the past two decades, loneliness has become more widespread and better understood. Recently, the University of Chicago’s General Social Survey, which monitors shifts in social changes and attitudes in the United States, found that the number of people who say they have no close friends had roughly tripled since 1985. This might seem strange considering the immensely interconnected world we live in now — or it might just feel familiar, perhaps acting as a confirmation of the feeling that social media exacerbates loneliness.

While the internet does connect us with more people, these relationships are more likely to be superficial, going no deeper than the posts you see or tweets you like. They lack the deep connections that are necessary and important in maintaining mental and cognitive health — the connections you need to not feel lonely.

The digitization of social spaces, combined with the increasing trend in North American cities of people living alone, has the risk of massively increasing loneliness in the population. Digitization isn’t all bad — I’ve made friends online and had meaningful interpersonal connections with them — but it can be harmful when all you have are surface-level relationships.

But something else is increasing this loneliness too. It’s a nefarious part of this whole problem: loneliness itself is contagious.

Studies have shown that nonlonely individuals who hang out with lonely individuals are more likely to end up lonely themselves. This happens mainly because when one person is lonely, their social habits tend to get rewired along with stress responses, making them act colder or less emotionally available to others they are friends with. This in turn leads to those friends feeling a disconnect between their desired and perceived social connectedness, creating spreading feelings of loneliness if this continues over time.

The contagious nature of loneliness is something that seems rather frightening and has the potential to exponentially increase the risk of loneliness as a serious illness in the population.

Feeling the pressure

Psychological effects like feelings of depression and anxiety are often described as some of the most major impacts of loneliness. And the reasons for this are entirely correlated with physiological and neurological changes — changes that are drastic enough to show up in simple MRI tests.

In an interview with The Varsity, U of T psychology professor Paul Whissell explained that loneliness leads to increased stress-like symptoms, which create the creation of more cortisol and noradrenaline than a healthy brain is used to. Cortisol and noradrenaline — a precursor to adrenaline — are hormones and neurotransmitters, chemicals that are used to signal messages and carry out processes all across the nervous system.

By increasing these neurotransmitters, the body and brain know that something — a stressor — is messing up the system. If a stressor exists for a short period, it leads to acute stress, which is the type you would experience writing an essay the night it’s due or writing an exam you haven’t prepared for.

Low to medium levels of this stress can lead to improved memory, cognitive ability, and more — which is why you might hear some people say that they work better under stress. However, increasing these levels even just a little too high will have the opposite impact, leading to cognitive impairment and slower memory. Think about how you feel when you write one paper last minute, compared to when you have papers due for three of your classes and a final exam tomorrow at 8:00 am.

But the good thing about acute stress is that the impacts are reversible. Exercising a bit, spending time with friends and family, or even looking at pictures of cute animals all have been shown to reverse these impacts and return our neurotransmitter levels to normal.

But the biggest issue comes in when the stressor doesn’t go away, such as when you’re under stress for weeks or months at a time — be it financial stress, academical stress, emotional stress, or anything else. And loneliness can cause effects that are just as bad, if not worse. When someone is lonely for long periods, stress-related hormone levels stay at their increased levels for far longer, resulting in patterns of chronic stress.

The cracks spread

With excessive or long-term activation of these stress responses, we start noticing all kinds of brain changes, particularly in behavioural and emotional processing.

Loneliness has a marked impact on the size of the hippocampus, the part of the brain responsible for memory. It leads to a shrinkage in the hippocampus. This reduced size has an obvious impact — a deficit in working memory — but it also contributes to increased levels of depression and anxiety. The areas supporting the hippocampus, such as the dentate gyrus, often shrink too.

The dentate gyrus is responsible for feeding information into the hippocampus and serves as the brain’s helper for learning and memorizing things. MRIs performed by neuroscientists at the Max Planck Institute for Human Development showed that individuals who were isolated and lonely had a dentate gyrus that had shrunk by an average of around seven per cent, leading to impaired learning and significant cognitive decline.

The shrinkage of these two parts of the brain has severe impacts on its own, but it also leads to an increased risk of other mental illnesses too. A smaller hippocampus, for example, increases the impact that traumatic events have on the brain and leads to earlier onset of depression.

It is worth noting, though, that a number of these studies just show correlation, not causation — loneliness may not necessarily be the cause for this cognitive decline.

Another part of the brain that is significantly impacted by loneliness and the stress responses it causes is the amygdala. The amygdala usually gets a bad reputation, since it’s labelled the centre for anxiety and fear, and some people assume we would be better off without it. But, really, the amygdala is responsible for processing various types of emotional stimuli, good and bad. It’s what comes alive when you fail an exam — but also when you find a joke funny and laugh.

Since the amygdala is so central to emotional processing and responses, it is also incredibly affected by stressful situations. Whissell told The Varsity that chronic stress literally “rewires the network which processes stress.”

“In the future, you respond differently, perhaps more strongly to stressors,” Whissell added. He explained that you become stuck in a loop where, any time there’s a stressor, you respond quickly and get stressed rapidly, leading to your brain rewiring further to anticipate stress.

You can think of this stress response pathway like a forest, which starts with no discernible route through it. A stressor appears in the form of a lone hiker, walking through the forest to get from point A to point B, leaving not much of a trail behind. The hiker then posts about this forest in an online forum, which means more hikers travel through it, making it easier to notice the path and walk along it.

As you continue staying in that stressful environment, more and more hikers appear, until, eventually, there’s a constant stream of tourists and hikers walking along, disrupting the local ecosystem and forming a path that makes it nearly effortless to walk through the forest.

The formation of this forest path is similar to how stressors and neurotransmitters rewire your brain to make it easier to get stressed out each time you face chronic stress.

This response is also why we see people who are lonely struggle to get out of that loneliness, no matter the help they receive. It isn’t just that they struggle to make friends or can’t socialize, but rather that they have been rewired to get stressed easier and become lonelier, making it hard to reverse these impacts.

While we can just look at the neuroscience and psychology of loneliness, it’s also important to consider the social aspect, which seems especially pertinent now, during the pandemic, when social isolation has become an important metric. When we are affected by loneliness, many of us tend to push others away, despite needing that social interaction.

And, ultimately, loneliness affects us all. While there is much more to learn about the effects of loneliness in society, one thing is for certain: we can’t fight it on our own.