Your Brain on Drugs: Dopamine and Addiction

What is happening to the neurochemistry of an addict's brain that makes that person so unable to do without cocaine, heroin, or methamphetamines?

"You can turn your back on a person, but never turn your back on a drug, especially when it's waving a razor sharp hunting knife in your eye," wrote gonzo journalist Hunter S. Thompson, no stranger himself to the compelling nature of addiction.


As has been demonstrated many, many, many times over, drug addiction is a powerful force that can take control of the lives of users. In the past, addiction was thought to be a weakness of character, but in recent decades research has increasingly found that addiction to drugs like cocaine, heroin and methamphetamine is a matter of brain chemistry.

Dr. Nora Volkow, the director of the National Institute on Drug Abuse, says that the way a brain becomes addicted to a drug is related to how a drug increases levels of the naturally-occurring neurotransmitter dopamine, which modulates the brain's ability to perceive reward reinforcement. The pleasure sensation that the brain gets when dopamine levels are elevated creates the motivation for us to proactively perform actions that are indispensable to our survival (like eating or procreation). Dopamine is what conditions us to do the things we need to do.

Using addictive drugs floods the limbic brain with dopamine—taking it up to as much as five or 10 times the normal level. With these levels elevated, the user's brain begins to associate the drug with an outsize neurochemical reward. Over time, by artificially raising the amount of dopamine our brains think is "normal," the drugs create a need that only they can meet.

"If a drug produces increases in dopamine in these limbic areas of the brain, then your brain is going to understand that signal as something that is very reinforcing, and will learn it very rapidly," says Volkow. "And so that the next time you get exposed to that stimuli, your brain already has learned that that's reinforcing, and you immediately—what we call a type of memory that's conditioning—will desire that particular drug." Over time, the consistently high levels of dopamine create plastic changes to the brain, desensitizing neurons so that they are less affected by it, and decreasing the number of receptors. That leads to the process of addiction, wherein a person loses control and is left with an intense drive to compulsively take the drug.

According to Volkow, the reason that dopamine-producing drugs are so addictive is that they have the ability to constantly fill a need for more dopamine. "So a person may take a hit of cocaine, snort it, it increases dopamine, takes a second, it increases dopamine, third, fourth, fifth, sixth. So there's never that decrease that ultimately leads to the satiety," she says.

Adam Kepecs, a neuroscientist at Cold Spring Harbor Laboratory says that addiction has to do with the brain's expectations. An emerging idea, he says, is that drugs basically "hijack" the brain's normal computational enjoyment and reward mechanisms.

"Let’s say you’re happy about a great chocolate ice cream," says Kepecs, as an example."Over time you learn to expect that the chocolate ice cream is really great and you have no more dopamine released in expectation of that when you receive it. Whereas, if you take an addictive drug, you can never learn to expect it because the drug itself will release an extra kick of dopamine. And when that happens, the value of that drug keeps increasing because now you’re learning that 'Wow my expectations were violated, therefore this must be much more valuable than what I thought before.' So basically what ends up happening: the dopamine system gets hijacked by these drugs."

Volkow notes that there are other components to addiction—like genetics and age of exposure—which is why not everyone who takes drugs becomes an addict. She says approximately 50% of the vulnerability of a person to become addicted is genetically determined, and research indicates that if a person is exposed to drugs in early adolescence they are much more likely to become addicted than if they were exposed to the same drugs as an adult.

Takeaway

One of the key functions of the neurotransmitter dopamine is to create feelings of pleasure that our brains associate with necessary physiological actions like eating and procreating. We are driven to perform these vital functions because our brains are conditioned to expect the dopamine rush that accompanies them.

Addictive drugs flood the brain with dopamine and condition us to expect artificially high levels of the neurotransmitter. Over time, the user's brain requires more dopamine than it can naturally produce, and it becomes dependent on the drug, which never actually satisfies the need it has created.

More Resources

— "What Addicts Need," 2008 article in Newsweek about how scientists are using insights about neurochemistry to treat addiction.

— "Addictive Research," 2007 article in TheScientist.com describing the latest

— University of Texas Addiction Science Research and Education Center description of the role dopamine plays in addiction.

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The 'People Map of the United States' zooms in on America's obsession with celebrity

Image: The Pudding
Strange Maps
  • Replace city names with those of their most famous residents
  • And you get a peculiar map of America's obsession with celebrity
  • If you seek fame, become an actor, musician or athlete rather than a politician, entrepreneur or scientist

Chicagoland is Obamaland

Image: The Pudding

Chicagoland's celebrity constellation: dominated by Barack, but with plenty of room for the Belushis, Brandos and Capones of this world.

Seen from among the satellites, this map of the United States is populated by a remarkably diverse bunch of athletes, entertainers, entrepreneurs and other persons of repute (and disrepute).

The multitalented Dwayne Johnson, boxing legend Muhammad Ali and Apple co-founder Steve Jobs dominate the West Coast. Right down the middle, we find actors Chris Pratt and Jason Momoa, singer Elvis Presley and basketball player Shaquille O'Neal. The East Coast crew include wrestler John Cena, whistle-blower Edward Snowden, mass murderer Ted Bundy… and Dwayne Johnson, again.

The Rock pops up in both Hayward, CA and Southwest Ranches, FL, but he's not the only one to appear twice on the map. Wild West legend Wyatt Earp makes an appearance in both Deadwood, SD and Dodge City, KS.

How is that? This 'People's Map of the United States' replaces the names of cities with those of "their most Wikipedia'ed resident: people born in, lived in, or connected to a place."

‘Cincinnati, Birthplace of Charles Manson'

Image: The Pudding

Keys to the city, or lock 'em up and throw away the key? A city's most famous sons and daughters of a city aren't always the most favoured ones.

That definition allows people to appear in more than one locality. Dwayne Johnson was born in Hayward, has one of his houses in Southwest Ranches, and is famous enough to be the 'most Wikipedia'ed resident' for both localities.

Wyatt Earp was born in Monmouth, IL, but his reputation is closely associated with both Deadwood and Dodge City – although he's most famous for the Gunfight at the O.K. Corral, which took place in Tombstone, AZ. And yes, if you zoom in on that town in southern Arizona, there's Mr Earp again.

The data for this map was collected via the Wikipedia API (application programming interface) from the English-language Wikipedia for the period from July 2015 to May 2019.

The thousands of 'Notable People' sections in Wikipedia entries for cities and other places in the U.S. were scrubbed for the person with the most pageviews. No distinction was made between places of birth, residence or death. As the developers note, "people can 'be from' multiple places".

Pageviews are an impartial indicator of interest – it doesn't matter whether your claim to fame is horrific or honorific. As a result, this map provides a non-judgmental overview of America's obsession with celebrity.

Royals and (other) mortals

Image: The Pudding

There's also a UK version of the People Map – filled with last names like Neeson, Sheeran, Darwin and Churchill – and a few first names of monarchs.

Celebrity, it is often argued, is our age's version of the Greek pantheon, populated by dozens of major gods and thousands of minor ones, each an example of behaviours to emulate or avoid. This constellation of stars, famous and infamous, is more than a map of names. It's a window into America's soul.

But don't let that put you off. Zooming in on the map is entertaining enough: celebrities floating around in the ether are suddenly tied down to a pedestrian level, and to real geography. And it's fun to see the famous and the infamous rub shoulders, as it were.

Barack Obama owns Chicago, but the suburbs to the west of the city are dotted with a panoply of personalities, ranging from the criminal (Al Capone, Cicero) and the musical (John Prine, Maywood) to figures literary (Jonathan Franzen, Western Springs) and painterly (Ivan Albright, Warrenville), actorial (Harrison Ford, Park Ridge) and political (Eugene V. Debs, Elmhurst).

Freaks and angels

Image: Dorothy

The People Map of the U.S. was inspired by the U.S.A. Song Map, substituting song titles for place names.

It would be interesting to compare 'the most Wikipedia'ed' sons and daughters of America's cities with the ones advertised at the city limits. When you're entering Aberdeen, WA, a sign invites you to 'come as you are', in homage to its most famous son, Kurt Cobain. It's a safe bet that Indian Hill, OH will make sure you know Neil Armstrong, first man on the moon, was one of theirs. But it's highly unlikely that Cincinnati, a bit further south, will make any noise about Charles Manson, local boy done bad.

Inevitably, the map also reveals some bitterly ironic neighbours, such as Ishi, the last of the Yahi tribe, captured near Oroville, CA. He died in 1916 as "the last wild Indian in North America". The most 'pageviewed' resident of nearby Colusa, CA is Byron de la Beckwith, Jr., the white supremacist convicted for the murder of Civil Rights activist Medgar Evers.

As a sampling of America's interests, this map teaches that those aiming for fame would do better to become actors, musicians or athletes rather than politicians, entrepreneurs or scientists. But also that celebrity is not limited to the big city lights of LA or New York. Even in deepest Dakota or flattest Kansas, the footlights of fame will find you. Whether that's good or bad? The pageviews don't judge...

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