http://en.wikipedia.org/wiki/Overdose
Some fascinating information on the biological process of heroin “overdosing”, as unearthed on one of my Wikipedia tours. (My, but my interests are wide-ranging!)
If you know of anyone with an addiction, wising them up to this research may be the next best thing to wising them up to quitting entirely.
Canadian researcher Shepard Siegel found, heroin abusers died taking the same dose of heroin they normally injected… There is compelling evidence that taking heroin in a new or different environment than usual may lead to overdose. In the terms of Pavlovian conditioning, the environment where the addict usually takes the drug (for example, if he always injects in the same room with the same people) serves as the conditioned stimulus, while the drug effect of heroin serves as the unconditioned stimulus. The body tends to try to maintain homeostasis, so it creates a compensatory response to counteract the effects of the drug… As the environment (CS) and drug effect (US) are paired over and over, the environment alone becomes sufficient to evoke the body’s compensatory response to heroin. This compensatory response, triggered by the environmental cues alone, is the conditioned response. As Pavlov’s dogs learned to salivate at the ring of a bell because the bell was often paired with food, a heroin user’s body creates a chemical, opposing response to heroin when the proper environmental cues are present. For this reason, the heroin abuser becomes able to take larger and larger doses of the drug, because his body creates a stronger and stronger compensatory response to its effects. “Overdose” often (more than half the time) occurs when the heroin abuser injects in a new environment. In this case, the environmental cues are not present, so the body does not produce the compensatory response required to make the usual large dose of heroin tolerable. The result is often death.