Addiction: a Fault of Chemistry

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This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Chemistry is at the brunt of it all, isn’t it? Addiction, the sinuous, stealthy disease is controlled by neurochemicals. Simple as that. You’re an addict or you’re not. Sounds easy and breezy, doesn’t it? The trouble and truth is, it could take years to figure out if you’re an addict. The truth is, you may never find out.

You can become addicted to drugs, alcohol, nicotine, exercise, love or just about anything. However, some substances are much more freely craved, more pleasurable to the masses than others. What’s pleasure? Food, sex, cocaine. At least, so indicate animals that press a lever for a drug, or pleasure, release in labs. Yes, they want cocaine. Yes, they want sex. Neurotransmitter levels in the brain skyrocket with certain drugs, flooding the neural wiring and stimulating dopamine circuit activity. In short: it feels good, at least in the beginning. So, what’s the difference between really liking and obtaining that glass of wine vs. having to have it?

Addiction arises out of the compulsion, the need, the craving to take a drug despite the negative consequences that become apparent: the loss of a job or a family, the alienation of friends or loved ones. Addicts have skewed brain chemistry. Most people try drugs or alcohol in their lifetime and for the small portion of this crowd suffering neurochemical imbalances, drugs fix their deficiency. They feel “normal” for the first time in their lives.


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To reach this normalcy, different addicts have different drugs of choice. This isn't always a matter of taste or preference -- shooting vs. snorting -- it's because cocaine addicts may be short one sort of neurotransmitter, while heroin addicts are short another. This shortage of correct combinations of neurotransmitters in the brain is known as Reward Deficiency Syndrome, or RDS. Without the proper neurochemical cocktail, addicts can suffer anxiety, a sense of unease or a feeling of incompleteness.

And actually, different drugs act as keys for those lacking various neurotransmitters. For those lacking dopamine, cocaine or amphetamines will be a fine neural cocktail. For those lacking GABA, benzodiazepines, such as Xanax, Valium or Ativan, will provide the kick. Natural alcoholics lack several types of neurochemicals and luckily (or unluckily), alcohol floods all receptors. For these people, finding the drug that equalizes their neurotransmitter shortage makes them feel better, at least at first.

Really, after an addict's repeated use, the brain starts to expect higher amounts of dopamine or another neurotransmitter, artificial though those drug methods may be in replacing a neurotransmitter that’s naturally lacking. The brain doesn’t know any better: high dopamine levels inherent with drug use become normal. When a person goes cold turkey, or stops using, the reward pathways in the brain shut down. The brain gets used to having a certain amount of drugs, and thus, becomes used to having certain amounts of neurotransmitters in its circuits, and when taken away it’s worse off than before. It craves the drugs to function.

Once the body normalizes to having a drug, or a certain level of dopamine in the system, a physical dependence develops. Say an addict becomes used to having cocaine daily. When a drug bleeds from her system, effects waning, illness manifests. For some, whole-body tremors develop, similar to early flu onset, while others like alcoholics become restless and stir-crazy. Because of this, users have to take more of the drug to avoid the pain and discomfort its absence creates. They have to take their drug of choice to feel normal, to equilibrate their neural circuitry, to simply exist without it.

If you never find your drug of choice, a dirty band-aid to the gaping wound of neurochemical imbalance, then perhaps you’ll never find addiction. For most of us, it isn’t worth the experiment to know. For others, it starts out innocently, by becoming too reliant on pain pills prescribed by a doctor after an accident. Would you be “better” with a neurochemical enhancement? I’ve been to rehab facilities and have seen good people lose their livelihoods, children and everything they hold dear. And thus, I ask: how could you say it’s not chemistry? How could you say it’s choice? Choice to feel robbed of free will? Choice to be dependent?

For addicts, it’s never over. A structure in the reptilian or old brain, the amygdala, causes the addict to crave a drug when she recognizes people, places, situations or patterns with which she's previously used. It’s instinct, without conscious thought. Consider this: if you’re drowning, you’ll push up for air. So will an addict, only her air is a drug.

For chemistry day, I say addiction is merely a disease of improperly-balanced neurons. Perhaps you already know that and perhaps it’s already obvious. If so: this is I celebrate. For more of a look, here are a few good reads:

For a dose of science: The Addiction Solution: Unraveling the Mysteries of Addiction through Cutting-Edge Brain Science

Drugs and the Brain

Molecules of Emotion: The Science Behind Mind-Body Medicine

For family members and friends coping: Addict in the Family: Stories of Loss, Hope and Recovery

About Cassie Rodenberg

I write, I listen, I research, I tell stories. Mostly just listen. I don't think we listen without judgment enough. I explore marginalized things we like to ignore. Addiction and mental illness is The White Noise behind many lives -- simply what Is. Peripherals: I write on culture, poverty, addiction and mental illness in New York City, recovering from stints as a chemist and interactive TV producer. During the day, I teach science in South Bronx public school.

More by Cassie Rodenberg

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