How is it that one person can enjoy a couple of beers or a glass of wine now and then and go on with their life, while someone else becomes an alcoholic? If there were a single, simple answer to this question, addiction might well be a thing of the past, because we’d likely be able to respond with one single, simple treatment. Instead, we must deal with addiction as it is: a complex and chronic brain disease that can get its start through multiple pathways and which almost always requires a variety of strategies to bring under control.
But why is it that many use alcohol or experiment with drugs but only about 10% become addicted?
First, it’s important to realize that whether or not a person becomes dependent on a substance has nothing to do with moral failings or willpower. It has to do with how the brain and body respond to the substance. Some people are more vulnerable to addiction than others, and their vulnerability can spring from a variety of interrelated factors rooted in both nature and nurture. Among them:
Genetics. It’s long been understood that addiction runs in families; advances in the field of genetics are helping us understand why. There is no single addiction gene, but researchers believe there are likely several genes or gene combinations that influence whether a person starts using substances, how rewarding they find it and why some continue to use despite negative consequences. Genes also probably explain why one person finds alcohol thrilling while another can take it or leave it. Genetic factors are believed to make up about half of a person’s addiction risk, but it’s important to remember that genetics are not destiny. The science of how genes are expressed, called epigenetics, and whether they are, in a sense, turned “on” or “off,” is influenced by our environment and lifestyle, meaning making healthy choices can help to minimize the negative impact.
Brain structure and chemistry. Imaging technology allows researchers to look inside the living brain in a way that was once impossible only a couple of decades ago. So we now know that brain changes and abnormalities can be both a cause and an effect of addiction. For example, a 2012 study of a group of identical twins — one of the twins had an addiction history and the other didn’t — found that both twins had brain abnormalities such as less dense white matter in the front of the brain, which suggests less self-control, and more gray matter in the brain’s mid regions, which is connected to an ability to form habits. This finding is seen as strong evidence that some brains predispose people to addiction, if the person chooses to use substances. Why one twin chose to do so and the other was able to resist substance use is still being studied, but life experiences are thought to play a role. In short, our brains can set us up for addiction, but we do have power to overcome those deficits.
Environment and lifestyle. Circumstances such as whether a person was raised by loving caregivers or not, how well they were taught resilience and coping skills, how safe they feel in their home and neighborhood and whether they are victims of violence or abuse all play a role in addiction risk. Such stressors can lead the person to turn to alcohol or drugs to soothe disturbing emotions. The relief, though, is temporary, and the more the substance is used, the more the brain needs to achieve the same effect. This escalating use can change brain chemistry in ways that rob the person of their ability to choose. A negative environment can also put a person into contact with people who drink or do drugs, meaning substances are more accessible and use is more socially acceptable.
Mental illness. About half of those living with mental illnesses such as clinical depression and bipolar disorder develop a substance use disorder. It often grows out of an attempt to self-medicate the symptoms of the illness; the person is not seeking pleasure as much as fleeing pain. In the long run, however, alcohol and other drugs only make the problem worse, research shows. The result is often a vicious cycle in which the mental health issue and the addiction feed each other. These co-occurring issues must both be treated for long-term healing.
Onset of use. The sooner a person starts using alcohol and other drugs, the greater the addiction risk. That’s because the brain is still forming up until about a person’s mid-20s, and drugs disrupt reward circuitry in ways that impair control. Research finds that those who start drinking before age 15, in fact, are about five times more likely to abuse or become dependent on alcohol than those who waited to drink until they were 21 or older.
From Risk to Recovery
Whether or not a person takes that first drink, then, is a matter of choice, but whether or not it becomes a problem is a matter not of character but of the combined power of genetics, lifestyle, environment, brain chemistry, mental health and age. Although the odds may seem stacked against some, the good news is that change is possible, even at the genetic level, and addiction treatment can not only provide needed support but actually help heal the brain — although it may always retain an increased vulnerability to relapse.
So, when asked why some become addicted and others don’t, I remind my questioners that, to a large degree, it’s the luck of the draw. Addicts often face contempt for their alcohol and drug dependence and the trouble it brings to their lives and the lives of those around them. But for those who face the hard reality that they can’t take a drink and walk away, a more appropriate response is compassion.