Can You Be Predisposed to Addiction?

Your genes affect your hair color, height, personality, and even your music taste. But can they go so far as predisposing you to a substance or behavioral addiction? Research says yes—but the reasons aren’t as cut-and-dried as having a certain gene or not. 

But in any case, it’s crucial to note that being predisposed to addiction doesn’t mean you’ll become addicted. Other factors contribute much more heavily to addiction, like your environment, life situation, past traumas, and more.

When The Apple Doesn’t Fall Far From The Tree

Certain genetic functions and traits can pass through families and predispose you to addiction, much like being predisposed to a condition like diabetes, depression, or heart diseases. The DNA you inherit can make you up to twice as likely to develop an addiction compared to someone with a different genetic makeup. 

So if your parents or grandparents have had an addiction, you’re more likely to develop one too. The likelihood varies slightly by substance, but hovers around 2x for most. 

This phenomenon has been meticulously studied and documented, mainly because it can seem so counterintuitive. If you see first-hand how an addiction has hurt a parent and affected your life, falling into the same patterns would seem like the last thing you’d expect to happen. But those genetic variables, plus your environment and life history, can turn casual substance use into an addiction right under your nose.

Genes Related to Addiction

Several genes code for different traits and predispositions that can lead to addiction. These genetic influences show a pattern of causation, but the exact reasons for those patterns isn’t as well-known or understood, yet. Here are a few examples of specific genes and genetic variants that can predispose someone to addiction:

• One variation of the dopamine receptor gene can make you more susceptible to the addictive effects of substances because it changes how substances influence your brain’s reward pathway.
• Variations in genes Per1 and Per2 can trigger someone (especially a teenager) to drink more alcohol than another, especially when stressed.  
• People can be more likely to develop an alcohol or opioid addiction if they have a certain variation in their mu opioid receptor gene.
• Dual copies of a gene called CHRNA5 makes people twice as likely to become addicted to nicotine, since the coding of that gene makes cells more sensitive to nicotine.

Is There an “Addiction Gene?”

In short, no. No one gene codes someone to become addicted to substances. And even for the genetic variations that can lead to addiction, it’s not a given that having those WILL make you addicted. That’s because addiction is the product of much more than your DNA. 

While there are “risk genes,” these aren’t the same as a gene that guarantees addiction. More often, genetic addiction risks relate to how your brain processes risk and reward, and if you’re more or less impulsive. How your brain regulates dopamine signaling also contributes to addiction risk, which is determined by your genes and various genetic variants.  

The Role of Epigenetics

Your behaviors and environment can activate or deactivate parts of your genes, a process called epigenetics. These changes aren’t to the DNA itself, but rather how your body reads and interprets genetic sequences. This can result in more or less proteins being made and when your body makes it, which can have cascading effects throughout your body. Epigenetic changes are reversible, unlike DNA mutations. They’re also what determines the function of your cells, like whether they become heart cells or nerve cells. 

A change in your behavior or environment could result in an epigenetic change that makes you more susceptible to addiction. For example, a highly stressful situation (like job loss) could vary how your body reads a sequence of DNA, triggering the small biochemical changes that make you more susceptible to addiction—like altering how your reward pathway handles dopamine. 

The epigenetic changes that make addiction more likely can happen with or without the inherited changes that can predispose you to addiction. 

Stress and Trauma as Triggers for Change

Trauma at any stage in your life can result in epigenetic changes, designed to help you survive in some way. These changes can also be passed down from a mother to her child. For example, mothers who experience greater stress and poor nutrition during pregnancy pass down epigenetically altered genes and the higher risk for diseases and addiction.

Chronic stress associated with trauma or other events can change how genes are expressed. The hormone released when we’re stressed, glucocorticoids, makes these changes through epigenetics. Other physiological changes related to hormones like adrenaline and cortisol also make epigenetic changes, altering how genes are read and expressed. When these changes affect your reward pathway, decision-making skills, and dopamine levels, you can become more predisposed to addiction.