Cliff Notes from Time Magazine’s “The Science of Addiction”
In case you don’t have the “Time” to read all 94-pages of their special edition, here are some of the highlights I pulled while going through it.
©The Editors of TIME. TIME The Science of Addiction.
An Introduction to Addiction
Almost anything deeply enjoyable has the potential to be addictive.
Everyone will become an addicted person if sufficiently exposed to drugs or alcohol.
For as long as human beings have had ways to feel good, we’ve struggled to know when it’s time to stop.
“Humans in my view will always want to experiment with things that make them feel good.” — Nora Volkow, director of NIDA (National Institute on Drug Abuse)
Addiction is defined as a chronic relapsing behavior in the face of negative consequences; the overwhelming urge to continue something you know is bad for you. It is such a harmful behavior, in fact, that evolution should have long ago weeded addiction out of the population.
“In all my years as a physician, I have never ever met a person who chose to be an addict, nor have I ever met someone who chose to be obese” — Nora Volkow, TedMed talk.
For a species wired for survival, we have an odd habit of getting hooked on things that can kill us. New research is revealing why — and opening the door to the long-dreamed-of cure.
How Does Addiction Work?
The behavior becomes a habit, the habit becomes a compulsion, and the compulsion becomes the life-wrecking disease that is addiction.
No one knows the exact cause of addictions, why some people are claimed by them while others can thread the needle of enjoying some indulgences but pulling up short before some becomes too much.
What happens in the brain?
1. We feel good when neurons in the reward pathway release a neurotransmitter called dopamine into the nucleus accumbens and other brain areas.
2. Neurons in the reward pathway communicate by sending electrical signals down their axons. The signal is passed to the next neuron across a small gap called the synapse.
3. Dopamine is released into the synapse, crosses to the next neuron and binds to receptors, providing a jolt of pleasure. Excess dopamine is taken back up by the sending cell. Other nerve cells release GABA, an inhibitory neurotransmitter that works to prevent the receptor nerve from being overstimulated.
4. Addictive substances increase the amount of dopamine in the synapse, heightening the feeling of pleasure. Addiction occurs when repeated drug use disrupts the normal balance of brain circuits that control rewards, memory and cognition, ultimately leading to compulsive drug-taking.
Nature vs. Nurture?
The causes of addiction, much like the individuals it affects, are complexly unique. But from behavioral fixations to chemical compulsions, answers may lie in our brains, our genes, and the greater world around us.
For centuries the “nature vs. nurture” debate cast a long shadow over the study of human behavior, including the phenomenon of addiction.
Experts now recognize that every human being is the product of both DNA and environment, which interact in endlessly complex ways to produce any number of outcomes. But that’s not to say the ratio of genetics to environment is the same from person to person. Just as one person’s genetic risk for heart disease or diabetes differs from another’s, not everyone’s risk for addiction is the same.
Researchers have identified specific genetic variables that, in some cases, can substantially raise or lower the likelihood that someone will “experiment” with addictive substances or go on to develop an addiction.
Based on this finding and their subsequent analysis, the study authors determined that between 48% and 58% of a man’s risk for an alcohol-use disorder is dependent on genetic variables, while the remainder of his risk comes down to environmental factors.
Research in the journal JAMA Psychiatry has determined that, when it comes to a young person’s risk for developing an alcohol-use disorder, environmental influences play a larger role than genetics. But this balance flips during adulthood. Once people reach their mid-20s, approximately, genetic factors seem to take the wheel and drive the larger share of the risk for addiction.
“Genetics are not destiny… No one is born with DNA that preordains a life of addiction.”
Research Developments & Findings
Predicting Addiction
Paulus found that 80 to 90% of the time, he could accurately predict who would relapse within a year simply by examining the brain scans of Methamphetamine users. Scans showed that there were reduced levels of activation in the prefrontal cortex where rational thought can override impulsive behavior. It’s impossible to say if the drugs might have damaged theses abilities in the relapsers — an effect rather than a cause of the chemical abuse — but the fact that the cognitive deficit existed in only some of the meth users suggests that there was something innate that was unique to them.
But just as there are two ways to stop a speeding car — by easing off the gas or hitting the brake pedal — there are two different possibilities for muting addiction. If dopamine receptors are the gas, the brain’s own inhibitory systems act as the brakes. In people with addictions, this natural damping circuit, called GABA (gamma-aminobutyric acid), appears to be faulty.
Sex differences
Sex hormones may also play a role in how people become addicted. Studies have shown, for instance, that women may be more vulnerable to cravings for nicotine during the latter part of the menstrual cycle, when the hormones progesterone and estrogen are released.
Females produce less alcohol dehydrogenase — the first enzyme in the stomach lining that starts to break down the ethanol in liquor — and less total body water than men. Together with estrogen, these factors have a net concentrating effect on the alcohol in the blood, giving women a more intense hit with each drink.
The role of stress
Another fundamental target for addiction treatments is the stress network. Animal studies show that stress can increase the desire for drugs. In rats trained to self-administer self-administer a substance, stressors such as a new environment, an unfamiliar cage mate or a change in routine lead to more substance use. Among higher creatures like us, stress can also alter the way the brain thinks, particularly the way it contemplates the consequences of actions.
Research from the University of North Carolina has found that people who are genetically predisposed toward internalizing are at greater risk for depression and anxiety. And studies have found that specific genetic variants that are associated with internalizing are predictive of greater risk for substance-use disorders. “Individuals who are more genetically predisposed this way often use substances to cope or to manage emotions,” Dick says.
It turns out that phobias and drugs exploit the same struggle between high and low circuits in the brain.
Food
Some numbers suggest that food may be even more addictive than drugs. About 30% of people who try heroin become addicts; the same goes for about 16% of cocaine users. Those figures are beaten easily, however, by the more than 40% of Americans who are obese and the overall 71.6% who are overweight — which suggests at the very least an unhealthy dependency on food.
In some ways, of course, food is more insidious than drugs, because there’s no such thing as abstinence, no such thing as never starting in the first place, no such thing as being able to say, “Food? Never touch the stuff. I saw what it did to my uncle.”
Sweets are a trifecta of irresistibles: SUGAR AND FAT AND SALT.
And it’s not only in humans that this happens.
In a 2013 study led by neuroscientist Joseph Schroeder at Connecticut College, researchers found that Oreos — an indulgent staple of the human diet if ever there was one — light up the neurons in the pleasure center of rats’ brains even more powerfully than cocaine does. And, like humans, the rats knew where to find the sweetest, fattiest, tastiest part of the cookie. “They would break it open and eat the middle first,”
The Road To Progress?
“When drug addicts or alcoholics ask us if they can ever use substances in moderation, we tell them no,” says Krantz. “Once your brain becomes a pickle, it can’t go back to being a cucumber.”
The sad part is that if you look at where addiction treatment was years ago, it hasn’t gotten much better — Martin Paulus, former professor of psychiatry at UCSD and now president of the Laureate Institute of Brain Research in Tulsa, Oklahoma.
“You have a better chance to do well after many types of cancer than you have of recovering from methamphetamine dependence.”
One out of every eight adults is simultaneously battling both alcohol and drug misuse.
Success rates of AA programs range from 5–50%, with many falling around 10%, but success rates can shoot up to 60% when treatment is ongoing (lasting long after their last drink).
One important discovery: evidence supports the 90-day rehabilitation model, which was stumbled upon by AA (new members are advised to attend a meeting a day for the first 90 days) and is a recommended duration of a stint in a drug-treatment program. It turns out that this is just about how long it takes for the brain to reset itself and shake off the immediate influence of a drug. Researchers at Yale University have documented what they call the sleeper effect — a gradual re-engaging of proper decision-making and analytical functions in the brain’s prefrontal cortex — after an addict has abstained for at least 90 days.
No two addictions are identical, nor are any two treatments. Still, nearly all people in recovery share some of the same treatment protocols, including:
◆ Detox support to achieve initial stability.
◆ Diagnosis and evaluation to address co-occurring disorders.
◆ A treatment plan with a trained specialist, appropriate therapies and goals for recovery.
◆ Ongoing peer support and accountability, such as a 12-step program with people in similar situations.
◆ Family support, including support groups for family members, education and family therapy.
Beyond the 12 Steps
Part of the problem with abstinence is that it leaves out problem drinkers who are unwilling or unable to give up booze entirely. Presented with a binary choice (keep drinking heavily or never have another drink), they choose the former. That may be why only 10% of problem drinkers never seek help.
Addiction is an intractable disease, driven by a complex network of biological, psychological and environmental contributors. It’s widespread — nearly half of Americans report having a close friend or family member who has been addicted to a substance — and it’s deadly. Last year, drug overdoses in the U.S. claimed more than 68,000 lives, exceeding the national toll from car crashes, AIDS or guns.
Every Addiction is Unique
Medications can work well, “but it depends on the person,” says Anna Lembke, the medical director of addiction medicine at Stanford University. “We don’t consider it strange that people who have cancer might respond to one chemotherapy rather than another . . . but for some reason, when it comes to addiction, people get all up in arms, as if there should be one magic wand that would solve the problem for everybody.” Alternative therapies could provide better options to patients who are ill-suited for current treatments — and options are what addicts need.
For now, it’s essentially an educated game of trial and error. Success depends on whether researchers select the correct targets straightaway.
“Treating addiction is never going to be one-size-fits-all,” Lembke says. “To build an effective infrastructure to treat patients who have serious addiction problems, we need to make sure they have access to all the available tools.”
Hope for the future
A rehabilitated addict is always in recovery because “cured” suggests that resuming drinking or smoking or shooting up is a safe possibility. But there are hints that a cure might not in principle be impossible.
