Dr. C. Thomas Brophy

She came into my office clean and sober, without any complaints. She stated that she simply wanted to say “thanks” for the treatment she received under my care. As I often do, I offered her a seat so we could catch up on the progress she has made in her recovery. For privacy purposes, we will call her Samantha.

Samantha had come quite a long way. When I first met her three years ago, she was addicted to opioids and methamphetamine. Back then she was fresh off having a child removed from her home by CYS, and was pregnant with another. I cautiously asked her for an update on the family situation.

“We are doing great actually. I now have both kids with me at home, and my parents help while I work and attend nursing school. If all goes well I should have my nursing degree by the end of this year!”

These success stories are the best part of my job. I relish them. But her facial expression suddenly changed to a frown, and she added, “I'm still paying for all those sins. though, and probably will for the rest of my life. My pastor says God has forgiven me, but I am not so sure I can forgive myself.”

I know that she is referring to the time she left her children unattended at home in hopes of quickly scoring dope. A concerned neighbor notified police, and officers found the kids alone and unkempt. Soon her entire world collapsed around her. The world judged her. And despite doing the hard work of getting clean and sober, she obviously continues to judge herself.

While she and her pastor may see those behaviors as a moral failing, ethics has little to do with the actual disease process behind addiction. To understand the abnormal behaviors that often accompany addiction, we must first take a look at the region of the brain most profoundly impacted by addictive substances. It’s called the limbic system.

Your limbic system is located in the midbrain, and it normally drives you toward food, water, sex, and shelter. All are incredibly important to survival. Food and water provide nourishment. Sex leads to procreation, allowing one to pass on their genes to progeny. And seeking shelter provides safety from environment and predators. Without these functions of the limbic system, our species would not last very long.

Our brains drive us toward the behaviors of obtaining food, water, sex and shelter by providing a feeling of pleasure when we are successful in our pursuit. This “pleasure” feeling is actually caused by the release of dopamine, a neurotransmitter present in the synapses of our brain. Dopamine is the feel-good chemical made and released by our neurons when we experience one of these pleasurable activities.

But what happens when drugs hijack the limbic system?

Interestingly, when we look at substances of abuse that lead to addiction, there is one common feature: they all have a major impact on the limbic system and seem to concentrate in this region. In addition, they release a wave of dopamine that can rarely be achieved through natural means. In other words, the pleasure from doing some drugs can significantly trump the pleasure that we can obtain even from amazing food or the best sex of our lives.

We actually see this result in real time when we observe the behavior of addicts. Consuming the drug not only becomes pleasurable, but in some cases an addict will forgo all other pleasures (food, water, sex, shelter and others) in pursuit of that drug. They will disregard aspects of life crucial to survival (and to the survival of their children in Sam’s case). But why?

This happens because the brain does not differentiate between dopamine from good sources versus dopamine from bad sources. It simply knows that it experienced a big wave of dopamine, and it wants MORE of that. It has evolved to want more. Even scarier, the brain will undergo a series of changes (called neuroplasticity) in response, with a goal of pushing that person toward behaviors that will result in more and more of the same.

That’s right — every time an addict abuses a drug, they undergo brain changes making it MORE likely for them to continue pursuing and consuming that drug. This becomes a vicious cycle, and as the addiction progresses, pursuit of the drug may become the one and only priority.

This is a small part of why treating addiction is so complex. We must first detox the drugs from a person’s body. Then we must stabilize their brain chemistry. Then we must work on “rewiring” all of those abnormal pleasure-reward pathways and allow the limbic system to heal, both of which can take a great deal of time. And this does not include all of the socioeconomic, cultural, legal, familial and other consequences that also must be considered.

A solid understanding of the neuroscience of addiction helps us treat patients more effectively. It also shows us that addiction is not a moral or ethical failing, but rather is the result of a diseased limbic system. I am not sure this will help Sam and her pastor feel better about her guilty conscience, but I still explain it all in hopes of alleviating her spiritual pain.

And at the end of the day, limbic systems can and do heal, especially with the correct treatments. And as is the case for Samantha, recovery is possible for everyone willing to recover.

Dr. C. Thomas Brophy is medical director at the Ellen O’Brien Gaiser Center.