Why does your parent have a drinking problem? Why are so many people dying from drug overdoses? Why is it so hard to quit smoking cigarettes?
Questions like these — and their complicated answers — show us just how much we have yet to learn about addiction. It’s not as simple as pointing to one specific cause as the source of an addict’s suffering. What’s more, there’s much variation in how addiction develops, the effects that it causes, and what’s required for recovery from one person to the next, further complicating the issue. Yet we continue trying to distill a formula or uncover a simple pattern hidden in the chaos, slowing chipping away at the block of marble to reveal the statue hidden within.
In the midst of so much uncertainty, a recent neurological study seems to have made a breakthrough when it comes to better understanding the disease of addiction.
Three Keys to Addiction in the Brain
What is addiction? Despite all that we know, whatever short answer we provide will always feel somewhat unsatisfactory because no short answer can encapsulate the many variables that influence or underlie a substance use disorder. In short, you might say that an addiction is a disorder in which the brain’s ability to make good choices is compromised. But how do you explain the variability? Why do different substances and circumstances and social influences cause people to experience addiction so differently?
According to a recent study from the National Institute on Alcohol Abuse and Alcoholism, addiction can be cleanly broken into three elements (or functional domains) that make up the neurocircuitry of addiction: executive functioning, incentive salience and negative emotionality.1
The idea that addiction can be broken into three neurological parts was inspired by a major shortcoming of current addiction diagnoses. Methods used today have been largely insufficient when it comes to accurately identifying and diagnosing individuals who suffer from addiction because of the numerous ways in which a person’s addiction can vary considerably from the addictions of others.
The first component of addiction neurocircuitry is executive function, which is a term known to more broadly refer to the skills a person uses to organize and act upon information.2 More specifically, executive functioning encompasses such skills as emotional control, flexibility or adaptability, impulse control, planning and prioritization, organization, task initiation, and self-monitoring.
With children and adolescents, executive functioning tends to be limited, acute and focused on the short-term, but we become better able to consider larger bodies of information and the broader strokes, so to speak, as we mature into adulthood. However, alcohol and drug abuse are known to cause problems with executive functioning, especially as the abuse becomes more severe and frequent over time and results in dramatically lower inhibitions, trouble with long-term planning, poor attention span, and the ability to make decisions based on prior experience.
After executive functioning, incentive salience is purported to be the second of the three keys to the neurocircuitry of addiction and is a very common topic when it comes to addiction. Specifically, incentive salience refers to a state of desire or wanting that a person assigns to some type of stimulus. Many people confuse this with pleasure, but it should be known that incentive salience is actually quite distinct. Although it’s also related to the brain’s reward system and regulated largely by dopamine, incentive salience is a motivational component.3 In other words, it’s largely involved in incentivizing behavior, causing feelings of desire that make people want to do things, whereas the reward is the pleasure that would be felt upon actually acting on those desires.
A number of the decisions we make are related to executive functioning, such as choosing to eat when we feel hungry or go to sleep when we feel tired. Incentive salience would become involved when, for example, we become tempted to eat something that tastes good but is unhealthy rather than the healthier and less-tasty alternative. This is when things become more complicated. Incentive salience is usually balanced by things like outcome prediction and objectivity, which keep us from acting purely on our desires. However, addiction is known to cause major changes in the brain’s reward and pleasure circuits. As a result, alcohol and drugs are attributed outsized salience, making them much more important than any alternatives.
Compared to the previous two, negative emotionality is perhaps the simplest and most straightforward component to understand. As the third and final part of the neurocircuitry of addiction, negative emotionality is a personality trait that some people exhibit wherein they tend to be more prone to experiencing anger, stress, sadness and other negative emotions.4 While this might initially seem to be unrelated to a disease like addiction, negative emotions are known to be a very common substance abuse trigger. In fact, many first-time users seek alcohol or drugs after traumatic or emotional experiences and end up becoming addicted due to using a substance as a means of coping for an extended period of time.
In fact, many first-time users seek alcohol or drugs after traumatic or emotional experiences and end up becoming addicted due to using a substance as a means of coping for an extended period of time.
However, not only are negative emotions more likely to trigger substance abuse, but people with substance abuse disorders tend to exhibit negative emotions more frequently than those without, further suggesting some type of correlation. Therefore, many researchers agree that negative emotions, which are often collectively referred to as hypohedonia,5 make people susceptible to substance abuse and those who experience these emotions more frequently are likely to use alcohol and drugs to cope with them.
What Can We Conclude?
This enlightening look at addiction from a three-part, neurological perspective is important for a few reasons. First, it provides a simple yet comprehensive frame with which to understand an extremely complex disease. In fact, each of the three components in this framework sheds light on possible explanations for the conundrums inherent in addiction, which will aid in diagnosing and treating addiction as much as understanding it. Perhaps more importantly, it outlines a very clear pattern that underlies addiction while allowing for the variability that can make addiction so hard to detect. While this is far from a complete picture of addiction, it adds stability and clarity to a foundation on which an enormous body of knowledge continues to grow.