What If It Were You?
By: Cassandra Souleles
The question I get asked most about my research is: “Why addiction?”
My answer is always the same: “Because it’s my biggest fear.”
I then wait for the confused look that usually follows, and eventually the reassurance: “You don’t seem like the type. No need to worry about that.” But most people don’t understand that addiction doesn’t pick and choose who it affects; it doesn’t discriminate. It can happen to the homeless man on St-Catherine just as easily as it can happen to the CEO of a company, or even to you. The fact that a single decision to try a substance could fundamentally change the way the brain processes reward and motivation is terrifying.
I began truly understanding the power substances can have over our lives when I watched an interview with an individual struggling with addiction. The interviewer asked him what it felt like the first time he took heroin. His response was immediate: “It was the happiest moment of my life.” He then explains that after all these years of using, he still hasn’t felt the same level of euphoria as that first time.
After watching this interview, I understood why people give up everything for a drug. Imagine every moment that has ever brought you joy—a beautiful sunset, a vacation, a proposal, the birth of a child—and realizing none of them compared to the feeling of that substance coursing through your veins. Who wouldn’t want to chase that feeling? If we would do anything for the people who make us happy, why would it be any different for a substance that provides even more happiness than they do?
Many people hear stories like this one and think “If they chose to take the drug, they can choose to stop.” However, what follows is more complicated than simply choosing to continue using.
In an attempt to understand addiction better, I started looking into the neuroscience behind it. I learned that substances like cocaine and amphetamines act directly on the brain’s reward circuitry, rapidly increasing dopamine levels in a way that produces intense reinforcement and euphoria [1]. What surprised me most was not just the intensity of this response, but how quickly the brain begins to adapt to it. Even a single exposure has been shown to trigger measurable changes in gene expression, suggesting that the effects of a drug can begin far earlier than most people realize [2].
As I kept reading, I also came across evidence that some molecular changes can persist long after drug use stops. For example, dopamine transporter levels have been found to remain altered even after months of abstinence following chronic cocaine exposure [3]. That stuck with me, because it suggests recovery is not simply about “getting back to baseline,” but about navigating a brain that may have been fundamentally rewired. This doesn’t mean that every aspect of pleasure is permanently lost for these individuals, but it does help explain why addiction is not simply a matter of willpower or a single “choice.” Over time, the brain can become increasingly biased toward seeking the drug, often at the expense of other sources of reward.
So if addiction involves significant changes in systems responsible for reward, motivation, and control like many other psychiatric and neurological conditions, why is it viewed as a choice?
There seems to be a gap between scientific evidence and public perception when it comes to addiction, and I want to bring attention to what addiction actually is beneath the stigma: a disorder of the brain, not a failure of character.
This semester, I had the opportunity to teach a high school neuroscience class, where I devoted an entire lesson to addiction. As we learned how substances affect the brain’s reward circuitry, motivation, and decision-making systems, I watched many of the students’ assumptions of addiction start to change. This reinforced something I had already begun to believe: stigma often comes not from malice, but from a lack of understanding. Watching perspectives shift right in front of my eyes reminded me that research isn’t enough when it’s locked away in labs and journals. I want to continue to bring neuroscience into classrooms and other community venues, to educate people about addiction as a brain disorder, not a character flaw.
So when people ask me, “Why addiction?” My answer is still the same: “Because it’s my biggest fear.” Not just because I think it could happen to me, but because I know it could happen to anyone. That realization is what first drew me to addiction research. What began as fear became curiosity, and curiosity became a commitment to understanding the neurobiology of addiction and why it’s so often misunderstood.
There is still a disconnect between what we know about addiction and what we believe about it. I want to bridge that gap by translating neuroscience into understanding, replacing judgment with evidence, and helping reduce the stigma surrounding addiction. Because stigma does more than shape opinions; it prevents people from seeking treatment, influences public policy, and ultimately costs lives.
1. Volkow ND, Morales M. The Brain on Drugs: From Reward to Addiction. Cell. 2015 August 13;162(4):712-25. doi: 10.1016/j.cell.2015.07.046. DOI: 10.1016/j.cell.2015.07.046.
2. Fumagalli F, Franchi C, Caffino L, Racagni G, Riva MA, Cervo L. Single session of cocaine intravenous self-administration shapes goal-oriented behaviours and up-regulates Arc mRNA levels in rat medial prefrontal cortex. International Journal of Neuropsychopharmacology. 2009 April; 12(3):423–429, https://doi.org/10.1017/S1461145708009681
3. Nader, M., Morgan, D., Gage, H. et al. PET imaging of dopamine D2 receptors during chronic cocaine self-administration in monkeys. Nat Neurosci. 2006 July 9; 1050–1056. https://doi.org/10.1038/nn1737
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