This 45-Year-Old Study on Heroin-Addicted Vietnam War Veterans Reveals Why It’s So Hard to Break Addictions.


On June 17, 1971, the President of the United States, Richard Nixon, stood in front of a lectern during a press conference and declared drug abuse, “public enemy number one,” and continued to say that “in order to fight and defeat this enemy, it is necessary to wage a new, all-out offensive.” 3

7 months prior to this date, two U.S. congressmen, Robert Steele from Connecticut and Morgan Murphy from Illinois, traveled to Vietnam for an official visit and returned home with horrific news that stunned the public: over 15 percent of U.S. soldiers fighting in the Vietnam war were heroin addicts. 2

In response to these reports, President Nixon created a new executive agency— the Special Action Office for Drug Abuse Prevention—to promote prevention of “public enemy number one” and rehabilitation of Vietnam war veterans.

But Nixon wasn’t done waging this “new, all-out offensive.”

Nixon wanted to figure out what happened to the Heroin-addicted servicemen once they returned to the U.S. And so, he commissioned this task to Jerome Jaffe—the head of the new drug abuse office—who in turn recruited a researcher named Lee Robins to conduct an extensive study into the addicted servicemen.

The popular belief at the time was that Heroin is the most addictive substance and once you got addicted to it, you were hooked for life.

But when Robins reported her findings from years of research into Vietnam war veterans, something didn’t quite add up.

Robins discovered that the number of Vietnam servicemen who took Heroin one year after returning home to the U.S. was shockingly low: only 5 percent. And after three years only 12 percent relapsed. 3

Considering the relapse rates of drug addicts at the time hovered around 90 percent, Robins’ findings shook the foundation of everything the clinical world believed about addictions.

A puzzling question then is: why is it so hard to break addictions? And how did so many heroin-addicted Vietnam war veterans, break their addictions in such a short period of time? 

vietnam war veterans heroin addiction

Soldier Snorting Dope, Aldo Stephen Panzieri, 1969

Everything We Know About Addiction Is Wrong

In the early 20th century, a series of rat experiments were conducted to uncover the effects of drug addiction in humans, and some were displayed in the form of anti-drug television advertisements across the U.S.

One famous 1980s advertisement said: “Only one drug is so addictive, nine out of ten laboratory rats will use it. And use it. And use it. Until dead…. It’s called cocaine. And it can do the same thing to you.” 4

The experiment was simple: you take a rat and put it in a cage with two water bottles attached to it. One bottle is filled with only water. The other contains water laced with heroin or cocaine. Nine times out of ten, the rat will become addicted to the drug laced water, and keep coming back for more of it until it kills itself. 5

It was from these experiments that the widespread belief that drugs caused addiction emerged.

But in the 1970s, Bruce Alexander, a researcher at Simon Fraser University, conducted “Rat Park” experiments to challenge these ideas. 6

To do this, Alexander placed rats in two separate housing spaces. In one housing space, rats were isolated from other rats and lived in small metal cages. In the other, 16 to 20 rats of both sexes lived together in “Rat Park”— a large housing colony with climbing poles, balls, wheels, open-topped cages, and an abundance of food and sex—in short, heaven on earth for rats.

In both housing spaces, there were two separate liquids presented to the rats: one contained morphine (an opioid class of drug) and the other, only water.

The results from the experiments were astonishing.

Alexander discovered that the isolated rats consumed significantly more morphine solution than the social rats in the “Rat Park.” In fact, during one phase of the experiment where water and morphine were presented in alternative days, the “Rat Park” rats consumed even less morphine than they had done so in previous phases of the experiment.

Coincidentally, Alexander had stumbled into the same conclusions about addiction, that Robins had also discovered a few years earlier during the Vietnam war veterans heroin study.

This conclusion, which flies in the face of everything we think we know about addiction, was best summarized by Bruce Alexander himself:

“Addiction is an adaptation. It’s not you—it’s the cage you live in.” (Source: Chasing the Scream (audiobook): The First and Last Days of the War on Drugs). 7

The Hidden Force Behind Addiction

After Robins presented the study that delivered a heavy blow to widely held beliefs that heroin addiction was unbreakable, a puzzling question still remained: why did so many Heroin-addicted Vietnam war veterans break their addiction, almost overnight? 

To solve this head-scratching puzzle, Robins interviewed the war veterans and asked them to explain why they had stopped the use of heroin after returning back to the U.S. from Vietnam. 8

During the interviews, the Vietnam war veterans highlighted that heroin was much easier to obtain and use in Vietnam than back home in the U.S.

In Vietnam, soldiers could easily purchase heroin for an extremely low price of 6 dollars for a high purity bag (90 percent). Conversely, in the U.S., the price of heroin was much higher at 20 dollars for a street bag of 10 percent purity. 9

In addition, in Vietnam, Heroin could be easily smoked and did not need to be injected, unlike heroin use in the United States. This eliminated a major barrier to initiating the use of heroin.

All of this combined with a social network of heroin-addicted fellow soldiers, extremely poor living conditions and high levels of stress from warfare, created the perfect environment for heroin addiction.

But when the soldiers returned to the U.S. from Vietnam, they were exposed to a completely different environment.

They no longer woke up to rattles of gunfire in Vietnam jungles and loud noises of helicopter blades in the middle of the night. Neither did they live with heroin-addicted servicemen or the high stress of warfare.

Back home, the soldiers lived in much better living conditions, and like most American citizens at the time, they’d go to work during the day and spend their evenings with their families.

The war veterans also noted that the fear of arrest and imprisonment, and strong disapproval from friends and family were strong deterrents from the use of Heroin in the U.S.

In short, the environment in Vietnam made it much easier to get addicted to Heroin and much harder to break the addiction, than in the U.S. And vice versa.

The answer to puzzling question was simple: the main reason why the majority of Vietnam war veterans broke their Heroin addiction was not because of willpower or a change in attitude—it was because of a radical change in their environment.

This conclusion meshes well with studies that show that approximately 45 percent of what we do on a daily basis takes place within the same environment. 10

For example, the mere sight of the entrance to an office building or a regular smoking area, is a powerful environmental cue to a smoker to go to this location and repeat the habit of smoking.

Over time these environmental cues become so ingrained in our psyche that we repeat the bad behaviors on autopilot, even when we don’t want to i.e. eating ice cream in front of the TV, reading emails as soon as we wake up in the morning and browsing on social media during working hours.

This is why the hidden force behind addiction is environment, and the best way to break bad habits and change our lives for the better, is to radically change our environment.

Willpower isn’t Enough

The mass media has sold us on the idea that addictions and bad habits are primarily driven by chemicals in our body, genetics, and lack of willpower and motivation.

But as we’ve learned from the studies into the heroin-addicted Vietnam war veterans who returned home and broke their heroin addictions, the main reason why it’s so hard to break addictions is the environment.

The easier your environment makes it to act on a bad behavior, the less self-control you have to resist temptation and the harder it is to break the bad habit. And vice versa.

We’d like to think that we control our actions, but in reality, environment is the invisible hand that shapes our behavior and nudges us towards the destiny of our lives.

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1. Video excerpt of the press conference during which President Nixon declared drug abuse “public enemy number one.

2. Kuzmarov J. The myth of the ‘addicted army’: drug use in Vietnam in historical perspective. War Society 2007; 26:121–41.

3. Lee N. Robins, Darlene H. Davis, and David N. Nurco, “Robins L. N. The Vietnam drug user returns: final report,September 1973. Lee N. Robins et al., “Vietnam Veterans Three Years after Vietnam: How Our Study Changed Our View of Heroin,” American Journal on Addictions 19, no. 3 (2010), doi:10.1111/j.1521–0391.2010.00046.x.

4. Video footage of 1980s rat experiment advert

5. Morphine experiment. Nichols, J. R., Headlee, C. P., Coppock, H. W.: Drug addiction. I. Addiction by escape training. J. Am. Pharm. Assoc. 45, 788–791 (1956)

6. Alexander, B.K., Coambs, R.B., and Hadaway, P.F. (1978). “The effect of housing and gender on morphine self-administration in rats,” Psychopharmacology, Vol 58, 175–179.

7. Johann Hari (2015). Chasing the Scream : The First and Last Days of the War on Drugs. (audiobook).

8. Robins L. N. The Vietnam drug user returns: final report,September 1973.

9. Johnson B. D., Golub A. Generational trends in heroin use and injection in New York City. In: Musto D., editor. One Hundred Years of Heroin. Westport, CT: Auburn House;2002, pp. 91–130.

10. Neal, David & Wood, Wendy & M. Quinn, Jeffrey. (2006). Habits—A Repeat Performance