Brain Hijackers: The Biology of Addiction

Addiction to substances — alcohol, nicotine, opioids, stimulants, or sedatives — is a serious issue for many people, wreaking havoc on families and communities.

People’s brains change because these substances stimulate reward centers. That’s why long‑term addiction can have serious consequences. 

The biology of addiction helps explain why people go to such extraordinary lengths to seek the substances that harm them and the people around them.

Scientists are still studying the complicated dynamics of what long‑term addiction does to the brain. Understanding the basics of what changes in the brain can help us approach people with substance use disorders with compassion and get them the help they need to undertake the difficult yet rewarding process of healing. 

What Is Addiction?

Addiction is not a moral issue or a problem of not having enough willpower to stop using substances.

It is a brain disease. 

The National Institutes of Health (NIH) describes addiction as drugs and alcohol “hijacking your brain.”

“The brain actually changes with addiction, and it takes a good deal of work to get it back to its normal state,” says Dr. George Koob, director of NIH’s National Institute on Alcohol Abuse and Alcoholism. “The more drugs or alcohol you’ve taken, the more disruptive it is to the brain.”

Healthy Brain vs. Addicted Brain

Our brain rewards us with something called dopamine when we do things that are healthy: exercising, eating, spending time with people we love. Healthy brains also help us make choices about whether to do something or consume something.

But drugs and alcohol also stimulate the brain’s production of dopamine. Chemical substances often produce more dopamine than the natural amount. When people continually use the drug, the brain tries to adapt. That’s why people with substance use disorders want more and more of the substances.

They begin to crave the new level of stimulation, or arousal, and the brain adapts to the new amount of dopamine. Over time, people can take substances just to feel “normal.” They sometimes have trouble finding joy in the things that used to bring them pleasure. In other words, the substances have hijacked their brains.

When scientists conduct brain imaging studies of people with addiction, they find changes in the parts of the brain that regulate judgment, decision‑making, learning and memory, and behavior. 

In his presentation Addiction and Trauma Recovery: Through an IPNB Perspective, Anthony Nave, MA, LCSW, describes the process of addiction as a “short circuit that is like a highway, while the healthy process is more like taking the back road.”

The Prefrontal Cortex

Studies have shown that people who struggle with addiction often have damage in the part of their brain that helps them make decisions: the prefrontal cortex. Nave calls the prefrontal cortex the area of the brain that is your personality and the part that helps you understand how much of something is a good thing: “the brake in your brain.”

What happens if your brake is broken? For example, post‑traumatic stress disorder (PTSD) affects the prefrontal cortex in ways that activate the fight/flight/freeze response. 

Or what if your prefrontal cortex never gets a chance to get fully formed before you start rewiring it?

The prefrontal part of the brain doesn’t fully develop until people are in their mid‑20s, which is why teens can be especially prone to addiction. 

Risk Factors of Addiction 

Scientists have not identified one particular gene that makes people vulnerable to addiction, but it does appear to run in families. Other factors such as abuse, stress, or growing up with a family member with a substance use disorder can increase the possibility that someone will struggle with addiction.

Drug Misuse and Addiction, an article on the NIH website, lists the following risk factors for addiction:

• Aggressive behavior in childhood
• Lack of supervision from parents or caregivers
• Low peer refusal skills
• Drug experimentation
• Availability of drugs at school
• Community poverty

However, every risk factor has a complementary protective factor. Protective factors include a belief in self‑control, parental support, positive relationships, good grades, school anti‑drug policies, and neighborhood resources.

Understanding Withdrawal

After the brain gets used to a certain level of a chemical, stopping the substance can be difficult or dangerous.

Withdrawing from certain substances can be a terrible and scary experience. Withdrawal can trigger mental, physical, and emotional symptoms, including depression, anxiety, and sweating. 

Treatment professionals are trained to help people manage withdrawal symptoms and help them reduce the chance of relapsing.

Trauma Recovery and the Healing Brain

People with alcohol, nicotine, or opioid addictions can be prescribed medications that can help them detoxify and treat the physical addiction. Trauma‑informed treatments can help people create healthy neural pathways that can help them avoid relapse.

Because trauma and addiction are so interrelated, there is a good amount of overlap in the ways behavioral health professionals approach healing. 

Judith Herman, author of Trauma and Recovery, is a psychiatrist known for her research on treating survivors of incest and traumatic stress. She pioneered a recovery approach that follows a 3‑stage process, which Nave also promotes in his presentation.

1. Safety. When people feel safe in their attachments, environments, and relationships, their brains start exercising in positive ways. Nave calls it “chipping away at negative core beliefs and reframing them into a narrative of resilience.” At this stage, body‑spirit interventions, grounding techniques, and mindfulness can help people stabilize.

2. Remembrance and Mourning. There are several treatments that can be introduced to build on the supports and coping skills from the first stage: Eye Movement and Desensitization Reprocessing (EMDR), Prolonged Exposure Therapy (PE), Narrative Exposure Therapy (NET), Trauma-Focused Cognitive Behavioral Therapy (TF‑CBT), Somatic Experiencing Therapy, Trauma-Informed Art Therapy, and Trauma Recovery Group (TRG). Many of these therapies use a physical process to help a person build a story of resilience and heal the prefrontal cortex.

3. Reconnection. As people move forward in their lives, they continue to strengthen their brain pathways with new experiences and continued therapy.

The Resilient Brain

Addiction and substance use disorders are tricky and can be difficult to treat. 

But the good news is brains can change. 

In the same way that brains can become hijacked by substances, compassionate, trauma‑informed treatment can slowly unravel the damage and help people heal from addiction and trauma.