Packets of heroin, a syringe and a spoon are displayed at the Drug Enforcement Agency Thursday, Dec. 19, 2002, in Portland, Maine. (AP Photo/Robert F. Bukaty)

Heroin deaths are on the rise, according to the Centers for Disease Control. The overdose death rate from heroin doubled in two years, from 1 death per 100,000 population in 2010 to 2.1 deaths in 2012. These statistics are alarming, and they are likely to add to a collective heroin freak-out that's been ongoing since at least February this year, when Philip Seymour Hoffmann overdosed on heroin and some other drugs. But it's important to keep these numbers in context. To wit:

Heroin use is vanishingly rare.

We don't know exactly how many people regularly use heroin in the United States. That's partly because relatively few people actually use it, which makes counting these people via traditional means, like surveys, difficult to do.

A floor estimate comes from the National Survey on Drug Use and Health (NSDUH), which showed 289,000 monthly heroin users in 2013. That works out to about one tenth of one percent of all Americans aged 12+. There's good reason to suspect that people under-report heroin use, however. An alternative measure developed by researchers at the RAND corp. for the White House Office of National Drug Control Policy suggests there may be as many as 1.5 million regular heroin users -- that is, those who use the drug four days a month or more.

The RAND researchers went to heroic methodological lengths to reverse-engineer those figures from spotty available data, so there's a lot of uncertainty around them. But even if we accept them at face value, that would mean roughly one half of one percent of the U.S. population is a regular user.

In other words, heroin is one of the least-frequently used drugs in the U.S. The NSDUH data suggests that compared to heroin, Americans are four times more likely to use hallucinogens, five times more likely to use cocaine, 16 times more likely to use prescription drugs recreationally, and 85 times more likely to use marijuana.

Heroin use might be on the rise, at least a little bit.

RAND/ONDCP

Pay attention to the middle trend line in the chart above -- that's the best estimate for the trend in chronic (4 times monthly or more) heroin use from RAND/ONDCP, from 2000 to 2010. The RAND authors note a 25 percent increase in chronic use between 2007 and 2010, but they caution that we shouldn't read to much into it, given the great deal of uncertainty around the numbers. But they do seem to jive with "anecdotal reports about prescription opiates becoming a 'gateway drug' to heroin for some individuals," the authors write. "Indeed, new research from the CDC supports this contention, stating, 'Heroin use among nonmedical users of opioid pain relievers increased between 2002–2004 and 2008–2010, with most reporting nonmedical use of opioid pain relievers before initiating heroin.'"

A natural (and evidently unintended) consequence of the federal crackdown on prescription painkiller use has been that people switch over to heroin, which is cheaper and more readily available. Indeed, some experts think that the very low percentage of people currently using heroin, coupled with the high numbers of people using prescription painkillers, is cause for more concern than usual. "The pool of people who are dependent on prescription opiates creates tinder through which an expansion of heroin use could happen rapidly," RAND researcher Jonathan Caulkins said in an interview.

In other words, because heroin use is so low, it has nowhere to go but up.

Heroin is incredibly lethal...

According to research in the journal Addiction, it takes roughly 8 milligrams of heroin to get the average person high, and only 50 milligrams to kill them. That ratio of about 6 to 1 - between the lethal dose and the effective dose - is incredibly narrow compared to other drugs. The ratio for alcohol is 10 to 1, cocaine is 15 to 1, LSD is 1,000 to 1, and the ratio for marijuana can't be calculated, because marijuana has no known lethal dose. So it stands to reason that even a small uptick in heroin use will lead to a noticeable spike in heroin deaths.

... but painkillers kill far more people each year.

In 2011, the most recent year for which complete data is available, 4,102 people unintentionally overdosed on heroin. By contrast, 17,241 people OD'd on prescription drugs (for comparison, gun homicides killed over 11,000 people that year). "We just don’t have the same recognition that a prescription for opiates is a quite lethal product," he says.

Rather than focusing solely on heroin or on prescription drug deaths, Caulkins recommends looking at them in tandem - that will give us a sense of whether cracking down on prescription opiate use will lead to more overall deaths due to heroin substitution, or fewer deaths as more people kick the opiate habit completely. But we won't have a good sense of that for another few years.

Overreaction produces dumb legislation.

Some of the most counter-productive drug legislation in recent history has been the direct result of widespread freakouts over perceived "epidemics" of drug use. Mandatory minimum sentences for drug offenders, widely enacted in the early 1990s in response to perceived upticks in inner city drug use, stand out as one glaring example. Even as lawmakers on both sides of the aisle work diligently to roll back those laws today, some states are toughening penalties on heroin. Bobby Jindal recently signed legislation in Louisiana that doubles the mandatory minimum sentence for heroin dealers, despite considerable evidence that these laws do nothing to deter drug use.

Inasmuch as the Louisiana law deters users from voluntarily seeking drug treatment for fear of getting in trouble with the law, it may likely increase both overall heroin use rates, and deaths from the drug.

It is heartening, on the other hand, to see that some states are taking smarter approaches to heroin use. A package of bills currently being debated in New Jersey would, among other things, increase Medicaid payments to drug treatment providers, launch a statewide program for monitoring the opiate prescriptions, and funnel more money into substance abuse prevention efforts.

Overall, it's important for the public - and particularly the media - to keep some perspective when it comes to the numbers on heroin. It doesn't make a lot of sense to speak of "epidemics" when use rates continue to hover somewhere between 0.1 and 0.5 percent of the total population. And kneejerk legislating will only make the problem worse.

CORRECTION: An earlier version of this piece incorrectly attributed a comparison between firearm deaths and prescription pill deaths to Jonathan Caulkins.