|Ozzy and John, like 500,000 other heroin addicts in the US, getting ready for their busy day.|
"K.J. and his wife were heroin addicts. They would shoot up together at home, and they’d been doing it for about four years. When his wife decided it was time to quit, K.J. reluctantly agreed. But the next day he was hanging out with friends, and they bought some heroin together. Because he didn’t want his wife to know, he stopped instead at a public toilet and shot up. He never made it home.
The authorities attributed K.J.’s death to overdose, but Canadian psychologist Shepard Siegel thinks there’s something mysterious about this case (link is external). First, K.J. had taken no more than his usual dose, not enough to kill a seasoned addict whose body had built up significant tolerance. Second, none of K.J.’s friends who’d bought from the same dealer overdosed, so the batch clearly wasn’t tainted or especially potent.
We think of an overdose occurring when a person takes more of a drug than the body can handle. Heroin is an opioid painkiller, but if you take too much, it suppresses the respiratory system. You go to sleep, you stop breathing, and you never wake up.
However, Siegel maintains that K.J. didn’t die because he’d taken too much heroin. Rather, he died because he’d taken the usual amount in an unusual place. Apparently, doing drugs has something in common with investing in real estate—location is key. But why?
First-time drug users tend to start with a small, relatively safe dosage. But as they use the drug over and over again, their body learns to accommodate by adjusting its chemical processes. As tolerance develops, the addict needs a larger dose to get the same effect, and as the body adjusts to the new level, the user boosts the dosage once more. Eventually, the seasoned addict takes as a normal dose an amount that would kill a novice.
Because heroin is such a quick-acting drug, the body needs to prepare itself before the injection takes place. But how does the body know it’s time to ramp up its defenses? It takes its cues from the environment. If you always shoot up at home in the evening with your spouse, then these all become environmental cues that a jolt of heroin is coming, and the body prepares to chemically deal with the drug.
This is why, when K.J. took a similar dose in a familiar environment the day before he died, he was able to handle it. But the next day, when he shot up in an unfamiliar location, his body wasn’t expecting a hit of heroin, and so it wasn’t prepared to process it. The sudden influx of the drug overpowered his system and killed him.
Environmental cues serve as conditioned stimuli signaling to the addict’s body that the drug is coming, and the body prepares itself in response. This works the same way that Pavlov trained dogs to salivate to a bell. Ring a bell, give the dog some food, and it salivates. Repeat this several times, and the dog will salivate when it hears the bell. That is, the bell serves as a cue that food is coming, and the dog’s digestive system responds by preparing for it.
The idea that familiar environmental cues can help protect an addict from overdose may sound far-fetched. But in fact, Siegel argues, there’s considerable evidence to support the hypothesis. For example, several studies have found that the majority of apparent heroin overdoses did not involve lethal levels of the drug in the blood stream."
Siegel, S. (2016). The heroin overdose mystery. Current Directions in Psychological Science, 25, 375-379.