Is Substance Use Disorder a Brain Disease?

February 16, 2026 

John Makohen, Author

Tom O'Connor, Publisher

Why the Science Still Says Yes and Why That Changes Everything

Critics argue that labeling addiction as a brain disease undermines personal agency and hope. However, recent research indicates the opposite. Understanding the brain's role in addiction can lead to more effective treatment, greater compassion, and a clear path forward.

Addiction isn't a character flaw; it's a pattern written in the brain. The story we tell ourselves about substance use disorder influences everything: our behavior, our choices, our expectations, and our outcomes. For years, that story has been torn between two extremes: on one side, addiction is viewed as a moral failure—an outdated, shame-based model (like the one AA promotes) that blames people for their pain.

On the other hand, addiction is a brain disease, aiming to ground addiction in biology and offer a medical approach. However, in recent years, the brain-disease model has come under criticism. Opponents argue that it portrays people as powerless, ignores spontaneous recovery, and oversimplifies a deeply complex issue. While some of these critiques raise essential questions, they do not negate the core truth: addiction rewires the brain; recovery reprograms it. Understanding that process is key to real, lasting change.

A landmark 2021 paper by Markus Heilig and a team of leading addiction scientists revisits the brain disease model, not to defend it blindly, but to refine it with greater clarity and precision. Their findings provide a compelling case for why the neuroscience of addiction still matters and how it must evolve to reflect both the biology of compulsion and the reality of recovery.

Why the Brain Disease Model Still Matters

The core idea behind the brain disease model is simple: repeated substance use alters the structure and function of the brain. These changes impact motivation, stress regulation, decision-making, and reward, all of which are central to addiction.

Specifically, chronic substance use disrupts three major brain systems:

• The basal ganglia, which are involved in motivation and pleasure

• The extended amygdala, responsible for stress and negative emotions

• The prefrontal cortex, which governs impulse control and long-term planning

When these systems are affected, the result is a predictable pattern: intense craving, decreased control, withdrawal symptoms, and compulsive use despite the consequences.

This isn't just a theory. It's supported by decades of neuroimaging, animal research, and clinical evidence. Understanding addiction as a brain-based condition helped change policy and perception. It validated the need for treatment. It opposed criminalization. And it enabled people to say, "This isn't just my fault — and I can still take responsibility."

The Criticisms — And Why They're Not Wrong

Let's be honest: some of the resistance to the brain disease model of addiction isn't just trolling. It comes from knowledgeable and experienced individuals, including clinicians, researchers, and people in recovery, who identify fundamental gaps in the model's application.

And they're not wrong. But they're not telling the whole story either. Let us examine the most significant critiques and explain why they warrant closer scrutiny. It's important to acknowledge these valid criticisms to foster a respectful and open dialogue about the brain disease model and its implications.

1. "It's Too Deterministic." This is one of the loudest criticisms, and for good reason. When you tell someone their brain is "diseased," it can sound like a life sentence. Like they're broken. As they'll never change, that kind of messaging, especially when repeated by professionals or institutions, can kill hope before healing starts. Critics argue that this deterministic framing strips people of agency, telling them they're powerless over their choices. In the worst-case scenario, it turns the brain into an excuse: "It's not me; it's my dopamine." That's a fair concern. But it's not a flaw in science. It's a flaw in how it gets framed.

The brain disease model isn't about fatalism. It's about explanation. And more importantly, it's about direction. Yes, addiction alters the brain. However, the brain also has neuroplasticity—the ability to change, adapt, and heal. This means that recovery is not only possible but also expected when the appropriate conditions are in place. The determinist critique isn't wrong. But it misunderstands the model's purpose: not to say "you can't change," but to explain why change feels so damn hard—and why it's still possible. This understanding can empower individuals in recovery and give them hope for a brighter future.

2. "It Doesn't Explain Spontaneous Remission." This one's a reality check. Millions of people recover from substance use without formal treatment. No rehab. No therapist. No medication. They stop. Does that mean their brains were never "diseased"? Does it mean addiction is just a bad habit? Not quite. What it shows is that the trajectory of addiction is diverse. The brain disease model must account for that diversity.

Heilig and his coauthors argue that remission doesn't invalidate the model. It complicates it. This suggests that biology interacts with social context, personal values, and environmental change. Someone might stop drinking upon becoming a parent because they hit a financial wall. Because they finally moved out of a high-stress, high-risk environment. None of that erases the biological changes that occurred. However, it does highlight that people are responsive, adaptable, and capable of change without medical intervention. The brain disease model is not a rigid framework; it's flexible and can coexist with a better understanding of resilience, motivation, and natural recovery.

3. "There's No Single Brain Signature for Substance Use Disorder." Right again. Despite decades of research, no one has found a magic MRI scan or neural pattern that definitively says, "This person has substance use disorder." That frustrates some scientists—and fuels skeptics.

But here's the thing: almost no complex condition has a single neural marker. Not depression. Not anxiety. Not PTSD. Why would addiction be different? Addiction is heterogeneous. People use other substances for different reasons in various environments with different genetic vulnerabilities. Expecting a one-size-fits-all brain marker is like expecting every trauma survivor to have the same scar. Instead of searching for a singular "addiction fingerprint," researchers are now focusing on patterns—changes in brain regions related to stress, motivation, and self-regulation. The absence of a singular biomarker doesn't disprove the brain disease model; it just means we must accept complexity over simplicity. The criticism is valid. But it's based on an unrealistic expectation, not a failure of science.

4. "It Over-Focuses on Compulsion and Ignores Agency." This is the most philosophically loaded critique, where many people in recovery push back. They say, "I chose to stop using. I wasn't some helpless robot." They're right. The original framing of addiction as purely "compulsive" behavior, something people do over and over against their will, ignored the nuance. It implied that addicted people were mindless, driven only by chemistry. That's not how addiction works in real life.

People with substance use disorder often respond to incentives, consequences, and alternative rewards. They can delay use. They can seek help. Sometimes they can prioritize family over relapse. So, is addiction compulsive? Yes. But not always. And not in the absolute sense. Compulsion exists on a spectrum. It's not that people can't choose differently, but doing so becomes incredibly difficult due to altered brain function and social reinforcement. The revised model addresses this by making space for both compulsion and capacity. You can have a brain that's been hijacked and still work to regain control.

That's not a contradiction. That's the entire point of recovery. 

*Here's another article by John about Harm Reduction

So, Are the Critics Right? 

They're not wrong. But they're not entirely correct either. The critiques are helpful because they highlight how the brain disease model has been misused, misrepresented, or oversimplified. But they don't negate the core truth:

Addiction changes the brain. Recovery changes it again. Science plays a critical role in understanding and supporting that process.

If we stop evolving the model, we fail the people it serves. If we discard it entirely, we risk reverting to punishment, moralism, and denial. The future isn't about choosing between biology and behavior. It's about building a model that honors both.

Addiction Is Both Biology and Behavior

This is where the revised model shines. It doesn't pit the brain against the will, and it doesn't frame people as helpless or damaged. It recognizes something more accurate and empowering.

Yes, addiction alters the brain. But the brain is also the source of recovery. Neuroplasticity, the brain's capacity for reorganization, means that change is always possible. People can restructure the circuits that drive craving, habit, and avoidance with the right environment, support, and interventions.

As Heilig and his coauthors explain, addiction is best understood as a pattern involving both compulsion and choice. People may feel driven to use it. But they also respond to new opportunities, relationships, and resources.

This is why recovery isn't just about abstinence. It's about reshaping the brain's reward system to value connection, purpose, and self-regulation more than the substance ever could.

Why Denying the Brain's Role Does More Harm Than Good

It's tempting to reject the brain disease model completely, especially if it's been used to justify passivity or hopelessness. But denying the role of the brain in addiction isn't just intellectually dishonest. It's dangerous.

When we pretend addiction is "just a choice," we justify punishment over care. We withdraw resources from people who need them. We ignore the powerful biological forces at play. Worst of all, we rob people of the tools they need to change tools grounded in the very neuroscience we've chosen to ignore.

The revised brain disease model isn't an excuse. It's a framework. One that respects both the reality of compulsion and the possibility of change. It says: You're not broken.' Your brain is trying to survive in a world that taught it to seek relief at all costs. And you can retrain it day by day, behavior by behavior.

The Path Forward: A Call for Consilience

We need consilience, integrating disciplines such as neuroscience, psychology, sociology, lived experience, and cultural context. All of it matters.

Consilience is the principle that truth emerges when we integrate insights across disciplines. Addiction isn't something you can fully understand through biology alone. It requires input from neuroscience, psychology, sociology, and lived experience. Each offers part of the picture. Combined, they provide a more comprehensive and practical understanding of how addiction works and how recovery occurs.

This approach moves us past black-and-white thinking. Instead of debating whether addiction is a brain disease or a behavioral issue, consilience asks better questions. It acknowledges the complexity of human behavior and emphasizes that science and lived experience must work in tandem. That's how we build better systems, treatment, and outcomes.

Recovery is not one-size-fits-all, and neither is addiction. So the solution isn't picking a side. It's building a bigger picture.

• Biology explains the compulsive patterns and the rise of relapse.

• Behavioral science guides treatment and habit change.

• Social factors shape risk, resilience, and opportunity.

• Lived experience offers insight that no lab can ever match.

We don't need less science. We need better science. Science that serves people. Science

that adapts. Science that listens.

What This Means for You

If you're struggling with substance use:

• Your experience is valid, even if it doesn't fit the textbook

• Your brain has adapted, but it's not fixed in place

• You can recover — because change is built into your biology

If you're supporting someone:

• Compassion helps far more than shame.

• Understanding the brain can help you respond with more patience, not less.

• Their behavior isn't always under complete conscious control, but that doesn't mean they can't grow.

If you're working in the field:

• Be precise with language

• Teach the science without stripping away humanity

• Remember that no model is perfect, but this one still saves lives

Final Thought: The Science of Addiction Must Serve Hope, Not Replace It

Addiction isn't a moral failing. But it's not destiny either. It's a brain-based disorder that interacts with every part of a person's life, and recovery is possible not despite that reality, but because of it. We learn more every year about how the brain heals, how behavior changes, and how people reclaim agency after years of pain.

This isn't the end of the debate. But it's a better beginning. It is a beginning grounded in biology and built on belief, science, change, and the people at its center.

---

John Makohen also authored two influential books: A Heroin User's Guide to Harm Reduction: Staying Alive in the Age of Fentanyl and Xylazine and Resilience: Building Strength in Early Recovery. The first is a bold, honest survival manual for people who use drugs in today's overdose crisis. The second book is a straightforward guide with practical strategies for building strength and confidence during early recovery.

John is a frequent contributor to the Vital Voyage Blog, is on our Editorial Advisory Board, and is a key Subject Matter Expert.

If you enjoyed this article, 

Please forward this to a friend or colleague who might benefit from it!