Ordinarily, most of us don't consider the extent to which we are chemical creatures, which is probably as it should be. However, the recent influx of heroin into Massachusetts is a pointed reminder of our vulnerability to the addictive power of opiates. A number of unfortunate individuals, some of them adolescents, have received a crash course in the neurobiology of dependence, and its consequences aren't pretty.
Over the last four years, heroin has overtaken cocaine as the drug of choice of those coming into treatment. Purer and cheaper than ever, it seems less threatening to new users than in earlier heroin epidemics: It can be snorted or smoked, so the stigma associated with injection and the risks of needle-transmitted disease are avoided. At first.
Most, perhaps nearly all, heroin inhalers start out assuming they will never inject. But the sad fact is that many eventually will, as buddies who use needles persuade them that there's a better rush to be had, or that their drug dollar goes further when heroin powder is cooked up into an injectable solution.
What at first seems beyond the pale becomes a necessity as addiction takes hold, and then HIV, hepatitis, and other needle-transmitted diseases run rampant. Even those who are smart enough not to inject aren't immune from getting hooked, as statistics on treatment admissions show. Over 30 percent of those in Boston's publicly financed programs for heroin abuse primarily inhale or smoke the drug.
From all accounts, heroin delivers unparalleled pleasure, which is precisely why we shouldn't use it. We're all possessed of a ''reward pathway'' deep in the brain, bequeathed us by evolution, which makes us seek out those things - food, sex, approval, mastery, novelty - which have contributed to survival.
Heroin is particularly suited to giving us the reward - in spades - but what gets rewarded is drug-seeking and drug-using behavior, not anything like what nature originally ''intended.''
So we get drastically spoiled and sidetracked by heroin; nothing else in life compares with those first hits. But beyond that, heroin changes the brain so that it's less a matter of getting high than avoiding the misery of being ''drug sick.'' And some addictions researchers believe the changes are nigh irreversible.
If history is any guide, law enforcement efforts to block the supply of heroin and other drugs will have little impact on availability, which means that, short of emulating the Big Brother approach of Singapore, addictive substances will always be with us.
The challenge, therefore, is to deflect potential users - mostly adolescents and young adults - from experimenting with the cool new drug in town. But how?
Since teens detest the thought that anything might control them, prevention in communities and schools must send the message that anyone can be victimized by opiates. It's your very brain you put at risk, your very autonomy. In focus groups, teens tell us that this message is best delivered by peers who have fallen to addiction, or by educators who gain credibility by acknowledging the realities of adolescent substance use instead of hiding behind a simplistic ''just say no.''
Parents can help by staying connected with their children, but without being punitive, and by modeling moderate and responsible drinking if alcohol is used at home. Media campaigns must be tailored to an increasingly sophisticated young audience that is seriously unimpressed by drug war hype. Although any drug can be abused, teenagers know that substances differ in their risks, so an effective message about heroin won't necessarily work for marijuana.
Most basic, though, is making sure that youngsters have better things to do than get high, and have legitimate expectations for the future. Although even the most privileged adolescent can ''graduate'' from alcohol, cigarettes, and marijuana to hard drugs such as heroin, the chances of becoming a confirmed junkie are far greater when life opportunities are scarce.
This means making substantial investments in high-risk schools and communities to boost educational achievement, extracurricular activities, job placement, and ultimately each individual's sense of self-worth and responsibility. Neighborhood and peer norms condoning high levels of substance use can change if attractive alternatives exist, and creating these alternatives will pay off handsomely since it's far less expensive to educate than imprison, to prevent rather than treat.
Until we are willing to make these investments, cheap, pure heroin, as well as other drugs (alcohol and nicotine primary among them), will continue to take their toll, and we'll be left dealing with the detritus of addiction. In the short term, this means making treatment available on demand, and reducing the risks of injection-transmitted HIV and hepatitis by expanding needle exchange in Massachusetts.
But in the long run, to effectively combat our built-in vulnerability to drugs we must take on the whole prevention challenge: school, community, and jobs development, increased parental involvement, better substance abuse education, and more savvy media campaigns. The tide will turn when it becomes clear that life has a lot more to offer than a cheap high.
Thomas W. Clark is a research associate at Health and Addictions Research Inc. in Boston.