We discuss quite a bit in clinical practice about why we have mental health issues, and how a feeling of anxiety often has significant nuance in terms of diagnosis. Let’s start with good old-fashioned anxiety. Anxiety is the feeling of being in danger or there being some sort of threat when one is not present, and this comes down to how our brains are wired for survival.

First and foremost, our brains are wired to prioritize negative emotions in order to keep us safe. We are not truly at the top of the food chain, and primitive humans faced a great deal of threat. There was the risk of wild animals attacking us, as well as danger from other humans outside our tribe. Like rodents who seem to be fearful at all times, we had to keep our heads up and scanning for potential danger constantly. In other words, we had to maintain a baseline level of fear to detect potential threats and respond to them in order to stay alive.

I have made the joke with my patients that if they have a lot of anxiety, it is because they would have been remarkably successful as primitive humans. If, back when we were hunter-gatherers, I were picking flowers while they were on alert for predators, I was likely going to be lion food, and they were likely to survive. There may actually be evolutionary selection for anxious personalities, because heightened vigilance improved survival against threat.

Our first primitive need, then, is to be safe from danger. Our brain prioritizes this emotion above all others and is wired to pay close attention to negative emotions because they are associated with awareness of threat. Once we were actually safe, our brain then prioritized more positive emotions oriented around long-term survival. This is where dopamine and the reward system come in. If we were able to look around and confirm that we were safe, our brain would encourage us to do one of three things: eat, reproduce, and enjoy positive human connection. These are all behaviors that ensure long-term survival. We need nourishment. We need protection. Human connection and the creation of communities allowed us to share resources, work for the collective good, and find strength in numbers.

Food, sex, and human connection all release dopamine, which makes us feel good. But our brain is wired for short-term survival first, so if a threat was detected, the negative emotions of fear and anxiety would overpower positive emotions until we were safe again. Our brain listens to negative emotions more readily than positive ones because this prioritization of short-term survival was essential to our existence. That is how our brains grew and developed over tens of thousands of years.

In the last 2,000 years, the world has changed. We have seen the slow development of modern society. In the last 200 years, industrialization. In the last 50 years, the rise of technology. And in the last 20 years, the arrival of social media. And now, artificial intelligence. Unfortunately, this has been a recipe for disaster for the human brain. Our brains evolved to make us the most successful species on the planet given a very specific set of inputs and experiences: awareness of physical threats, and the ability to focus on long-term survival when danger was absent.

Into this equation, we introduced substances: cannabis, coca, alcohol from fermented plants. These are all things that hijack our reward system and distort how our brain understands long-term survival. Our brain gets tricked into thinking that substances help with survival because they cause dopamine release, and because substances release far more dopamine than we generate naturally, the brain begins to lose its appreciation for human connection, which is associated with comparatively lower levels of dopamine release than alcohol, fast food, or cocaine.

The last 50 years have brought technology, the internet, and social media, and with them, an entirely new set of challenges. The use of a screen is deeply unnatural to the human brain. We are wired to perceive reality directly. Our brains have not evolved over thousands of years to distinguish a screen from reality, and as a result, when we see things on a screen, our brain interprets them as real. This is why movies and television can have such profound effects on our emotions. We get drawn into believing that what we are seeing is part of the reality around us.

With social media, negative interactions trigger our survival instincts and produce intense emotions, including anger, fear, anxiety, and rage, because our brain interprets threats on a screen as real-life threats to our body and life. And if we are in perceived survival mode, we cannot enjoy positive human connection, because our brain is prioritizing what it believes is an immediate danger.

Facebook was founded on the idea that human connection is inherently good, and I agree with that premise, because positive connection is one of the core things our brain has evolved to value as part of long-term survival. However, on-screen interactions are something our brain does not know how to process. The technology is simply too new. Meaningful evolutionary adaptation requires something on the order of thousands of years, and yet we have human beings whose adult lives look fundamentally different from their childhoods because of rapidly changing technology. Our brains cannot adapt that quickly.

What does this mean clinically? I believe we must understand how our brains work in order to help our patients navigate an increasingly unnatural world. We must help them see screens for what they are: tools designed to capture attention and generate profit, which the brain interprets as reality, and which exert profound control over our emotions. We must help them understand that substances trick the brain into believing they serve long-term survival by flooding the reward system with dopamine, while simultaneously eroding the brain’s ability to find value in genuine human connection.

I believe fundamentally, and deeply, that social media is one of the most damaging developments in modern human history. I recognize that it can be used for good. I previously used LinkedIn myself to share my work in addiction medicine. But at its core, social media involves the deliberate manipulation of our time, attention, and emotions for profit, with insufficient recognition of the profound and troubling effect it is having on the human psyche.

Casey Grover is an emergency physician.