Twenty-nine years ago, I inherited something from my father I've carried with me ever since. I haven't seen him in a little over a decade, but he crops up in my subconscious at very specific times—when I feel the loopy satisfaction of a buzz from booze or beeline straight to my home bar after a tough day.
My dad had a brilliant mind and a seemingly endless intellectual curiosity; he was also an alcoholic and addicted to a litany of narcotics that ultimately led to the end of his career, the end of our family's relationship with him, and a ten-year sentence in federal prison on drug-trafficking charges. I spent my youth and adolescence watching him devolve into an abusive, violent tailspin, and I'll likely spend my adult life working to ensure that cycle is never repeated.
While it's not as simple as having a single "addiction gene," years of research shows children of addicts like me are predisposed to the same path, thanks to a spiderweb of genes and polymorphisms, or genetic variations, that can change how we react to substances, how likely we are to become dependent, how vulnerable we are to relapse. For addicts, genetic and environmental factors are both at play, and often intertwined. "About half of the risk of developing an addiction is explained by genetics and the other half by environment," explains Dr. Edward Nunes, a psychiatry professor within Columbia University's substance-abuse division. "It's important to be wary of simple explanations," he cautions. "Substance use disorders are very complex, determined by multiple factors, both genetic factors, features of the environment someone grows up in, and the current environment, including stress."
The way substances affect children of addicts has been of interest to researchers for decades, but just last week, Dr. Camron Bryant and his team at the Boston University Medical Center published the results of their work studying the impairment of a specific gene (casein kinase 1-epsilon, or CSNK1E), which they tested by injecting mice with both opiates and saline solution, designating a drug environment and a non-drug environment, and studying their locomotor activity, or their movement from one environment to the next. The researchers concluded that mice with a non-functional copy of CSNK1E were both more sensitive to the effects of opioids, and more sensitive to the rewarding property of the drug. It's obviously not on par with a human study, but Bryant adds that mice are typically accurate predictors of humans' addiction liabilities to different drugs. "Basically, if a mouse shows conditioned preference to a drug, humans are going to be susceptible as well," he says. "This, I think, shed important light on accumulating studies in humans, and suggests specifically that polymorphisms in this gene in humans may enhance susceptibility to the euphoric, pleasurable, addictive properties of opioids.
A few years ago, the same team found a similar genetic link with sensitivity to methamphetamines. "Acute drug sensitivity, vulnerability to the addictive properties… that's what we think this gene is important for," explains Bryant. He adds it's possible this gene could increase one's susceptibility to developing tolerance, affect one's withdrawal symptoms, and make it more difficult to quit and easier to relapse.
In other words, for those with addiction in their families, some research suggests our systems can be pre-programmed from birth to process certain substances differently and, cruelly, make us vulnerable to the very same substances that consumed our family members.
Having a family member with an addiction disorder doesn't automatically condemn me to share the same fate, but it adds a layer of complexity to my relationship with substances. I will never touch the kind of pills my dad abused. But I do find much sensory pleasure, social ease, and intellectual gratification in booze. I find that, most of the time, my relationship with alcohol is similar to that of my peers: fun, often a social lubricant, occasionally a crutch, and every now and then, after a particularly grisly night, something I swear off, at least for a little while. I love how a couple drinks seem to wash away my social anxiety, allowing a looser, funnier me to emerge, as effervescent and light as the bubbles in my champagne flute.
Most of the time. But it's the moments when I catch myself feeling the onset of a buzz and giddily, euphorically grasping for more; or the times when I purposely sink into a haze to dull the sharp edges of the day; or the times when I know I don't need another drink, but summon the bartender anyway—those are the times when I consider my own statistical likelihood of repeating the past.
It's a shitty inheritance: I'd much rather be entrusted with some cool antiques, lots of land, and a trust fund.
While the levels of heritability for addiction are different for each substance in question, "all addictions have at least some heritable component," explains Dr. Bryant. But, he adds, "there are non-heritable, environmental factors that can just as easily influence and increase your susceptibility as well, such as early life trauma, child abuse, and so on."
Dr. Harold Jonas, an addiction-treatment specialist and the founder of Sober.com, echoes this: "In my experience, once a person who has a family history of substance dependence engages with any drug, the 'witch's cauldron' of variables is more likely to attach than not," he says. "These [variables] are genetic coding, peer choices, family values, risk-taking personality, timing, and desire. Addicts grow from there. They do not fall off family trees, but they also do not fall far from them, either." Sharing the blood of an addict is one thing; witnessing and experiencing the lifelong consequences and conflicts of their behavior is another. Growing up in that kind of turbulent, unpredictable environment—it's enough to drive one to drink.
For myself and many I know whose family members have succumbed to addiction, this can manifest as a fraught relationship with substances, and a lifetime of stops, starts, self-scrutiny, and course-correction. Some of us take breaks, so we know stopping is an option. "Once or twice a year, I stop drinking entirely, just to make sure I still can," says one friend, whose mother has been an alcoholic for as long as she can remember. "I keep a stern eye on my own drinking because I'm terrified of ending up like her."
Still others eschew the substance in question entirely. "I think choosing not to drink was like a guarantee that I could separate myself from them," another friend, whose parents are both alcoholics, tells me.
For those of us who do choose to dabble in the vices of our mothers and fathers, it may seem like we're playing fast and loose with fate. As for doing our due diligence in ensuring that's not the case, Dr. Jonas says, "if a person in their mid 20s has a known history of alcoholism and/or drug addiction in their family, but they choose to drink socially, they should be hyper-vigilant" in looking for physical and behavioral signs of dependence.
Dr. Nunes adds that, while he would inform a patient with a family history that they're at increased risk, it still doesn't change the fundamentals of treatment: "I would ask them how much they are drinking; I would look for heavy drinking, defined as five or more drinks per day or a man and four or more for a woman, per NIAAA defined binge drinking guidelines; I would look for any pattern of regular drug use; I would ask them how alcohol or drugs make them feel, and if they really like the feeling, I would suggest that is a warning sign," he says. Mostly, he would counsel a patient that addiction isn't all their fault. "People with substance use disorders have a lot of stigma, and guilt and low self-esteem," he says. "They need help to understand this is a medical illness, not all their fault, and they should focus on what they can do to get better."
It's a shitty inheritance. I'd much rather be entrusted with some cool antiques, lots of land, and a trust fund than, say, a physiological shortcut to becoming a high-functioning alcoholic or a gene that makes powerful drugs feel even more powerful. Society tells us that addiction is a weakness. Science tells us addiction is, in part, written in our blood and stamped into our marrow. We're heirs to, and keepers of, the most fragile kind of heirloom.
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