Using Marijuana May Not Raise the Risk of Using Harder Drugs (but look at alternative explanation)

RAND's Drug Policy Research Center ^ | December 2, 2002 | RAND's Drug Policy Research Center

[unspun]

Using Marijuana May Not Raise the Risk of Using Harder Drugs

Marijuana is widely regarded as a "gateway" drug, that is, one whose use results in an increased likelihood of using more serious drugs such as cocaine and heroin. This gateway effect is one of the principal reasons cited in defense of laws prohibiting the use or possession of marijuana. A recent analysis by RAND's Drug Policy Research Center (DPRC) suggests that data typically used to support a marijuana gateway effect can be explained as well by a different theory. The new research, by Andrew Morral, associate director of RAND Public Safety and Justice, Daniel McCaffrey, and Susan Paddock, has implications for U.S. marijuana policy. However, decisions about relaxing U.S. marijuana laws must necessarily take into account many other factors in addition to whether or not marijuana is a gateway drug.

Support for the Gateway Effect

Although marijuana has never been shown to have a gateway effect, three drug initiation facts support the notion that marijuana use raises the risk of hard-drug use:

• Marijuana users are many times more likely than nonusers to progress to hard-drug use.

• Almost all who have used both marijuana and hard drugs used marijuana first.

• The greater the frequency of marijuana use, the greater the likelihood of using hard drugs later.

This evidence would appear to make a strong case for a gateway effect. However, another explanation has been suggested: Those who use drugs may have an underlying propensity to do so that is not specific to any one drug. There is some support for such a "common-factor" model in studies of genetic, familial, and environmental factors influencing drug use. The presence of a common propensity could explain why people who use one drug are so much more likely to use another than are people who do not use the first drug. It has also been suggested that marijuana use precedes hard-drug use simply because opportunities to use marijuana come earlier in life than opportunities to use hard drugs. The DPRC analysis offers the first quantitative evidence that these observations can, without resort to a gateway effect, explain the strong observed associations between marijuana and hard-drug initiation.

New Support for Other Explanations

The DPRC research team examined the drug use patterns reported by more than 58,000 U.S. residents between the ages of 12 and 25 who participated in the National Household Surveys on Drug Abuse (NHSDA) conducted between 1982 and 1994.^[1] Using a statistical model, the researchers tested whether the observed patterns of drug use initiation might be expected if drug initiation risks were determined exclusively by

• when youths had a first opportunity to use each drug

• individuals' drug use propensity, which was assumed to be normally distributed^[2] in the population

• chance (or random) factors.

To put it another way, the researchers addressed the question: Could the drug initiation facts listed in the first section of this brief be explained without recourse to a marijuana gateway effect?

Figure 1—Probabilities of Initiating Hard Drugs, Marijuana Users and Nonusers

The research team found that these associations could be explained without any gateway effects:

• The statistical model could explain the increased risk of hard-drug initiation experienced by marijuana users. Indeed, the model predicted that marijuana users would be at even greater risk of drug use progression than the actual NHSDA data show (see Figure 1).

• The model predicted that only a fraction of hard-drug users would not have tried marijuana first. Whereas in the NHSDA data 1.6 percent of adolescents tried hard drugs before marijuana, the model predicted an even stronger sequencing of initiation, with just 1.1 percent trying hard drugs first.

• The modeled relationship between marijuana use frequency and hard-drug initiation could closely match the actual relationship (see Figure 2).

The new DPRC research thus demonstrates that the phenomena supporting claims that marijuana is a gateway drug also support the alternative explanation: that it is not marijuana use but individuals' opportunities and unique propensities to use drugs that determine their risk of initiating hard drugs. The research does not disprove the gateway theory; it merely shows that another explanation is plausible.

Figure 2—Probabilities of Hard-Drug Initiation, Given Marijuana Use Frequency in the Preceding Year

Some might argue that as long as the gateway theory remains a possible explanation, policymakers should play it safe and retain current strictures against marijuana use and possession. That attitude might be a sound one if current marijuana policies were free of costs and harms. But prohibition policies are not cost-free, and their harms are significant: The more than 700,000 marijuana arrests per year in the United States burden individuals, families, neighborhoods, and society as a whole.

Marijuana policies should weigh these harms of prohibition against the harms of increased marijuana availability and use, harms that could include adverse effects on the health, development, education, and cognitive functioning of marijuana users. However, the harms of marijuana use can no longer be viewed as necessarily including an expansion of hard-drug use and its associated harms. This shift in perspective ought to change the overall balance between the harms and benefits of different marijuana policies. Whether it is sufficient to change it decisively is something that the new DPRC research cannot aid in resolving.

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^[1]In subsequent years, respondents have not been asked about their first opportunity to use various drugs.

^[2]That is, some people have a high or low propensity, but most people have a propensity near the middle of the range.

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RB-6010 (2002)

RAND research briefs summarize research that has been more fully documented elsewhere. This research brief describes work done in RAND's Drug Policy Research Center, a joint endeavor of RAND Public Safety and Justice and RAND Health. The research is documented in "Reassessing the Marijuana Gateway Effect" by Andrew R. Morral, Daniel F. McCaffrey, and Susan M. Paddock, Addiction 97:1493-1504, 2002.

Abstracts of RAND documents may be viewed at www.rand.org. Publications are distributed to the trade by NBN. RAND^® is a registered trademark. RAND is a nonprofit institution that helps improve policy and decisionmaking through research and analysis; its publications do not necessarily reflect the opinions or policies of its research sponsors.

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RAND Home Page

[tacticalogic]

And your point is?

Wheather you agree with marijuana prohibition or not, there are constitutional issues with the way it has been established. Or at least there are if you subscribe to the notion of the Constitution as an "enduring document" who's meaning can't be changed by simply deciding that it means something different now.

[Hebrews 11:6]

Why would the process be arduous every time?

The act of having to stop and do it. It may be that we're quarreling over nothing, because I agree we are to pray constantly and be soberly on-alert.

...was our revolting against Great Britain a Christian act?

That's rather the ultimate test case, isn't it? First, using the framework I've advocated, not unless continuing to remain British would break God's deeper laws, and many Tories didn't think so and remained loyal to Britain. The majority of colonists maintained it would, and they were careful to make exactly that case in their Declaration of Independence.

They began by citing as self-evident truth their unalienable rights, with which they were endowed by their creator. Then they demonstrated that Britain's rule had become destructive of those rights, thus giving them the Right and even "the duty" to throw off Britain's rule. After citing a long list of abuses they chronicled their efforts to work within the system, without success. Having made every legitimate effort to remain loyal, they came finally to "acquiesce in the necessity" of rebelling.

Perhaps one could argue the merits of their argument, but the fact is they structured it as I've outlined: obey unless God clearly calls to you not to. Therefore, I have every confidence that they were acting in that situation as God would have them do. It is interesting, I think, to note that there has never been much if any reconsideration of their basic position--that is, few if any have said they were wrong in their approach. Could they have endured longer? Beside the point--they endured plenty and made a handsome case for putting up with no more.

[headsonpikes]

"I think you should come up with a controversial title..."

How about "Totalibertarian Manifesto" ? ;^)

[unspun]

Ok, but in any case, those studies don't reflect the user who starts with Marijuana then switches to other blighting drugs.

There are so many people with so many positions on all this stuff anyway, that it's a free for all each time. Yeee - hooo !!!

[unspun]

// The new DPRC research thus demonstrates that the phenomena supporting claims that marijuana is a gateway drug also support the alternative explanation: that it is not marijuana use but individuals' opportunities and unique propensities to use drugs that determine their risk of initiating hard drugs. The research does not disprove the gateway theory; it merely shows that another explanation is plausible. \\

The basic principles of economics and marketing are borne out, in either case. Boiling it down to one short sentence: The more drugs are available on the market, the more use there will be, of a greater variety of drugs.

That's true to a saturation point, of course. I pray America never gets to that point, where every hungry soul has his fill of this society crippling vice.

[unspun]

Oh my, you're willing discuss this from a Christian discipleship* point of view, Heb? "You're a better man than I am, Gunga Din."
______________________________
*a.k.a., theology, but that word seems haughty to me.

If I may interject something that you may or may not take as germane, I tend to 'lecture' that when the Bible speaks of "civil authority," as it pertains to America, it means first the Sovereign People, first. We are the highest ranking authority in our land (and we elect and appoint public servants by o-u-r constitutions).

[unspun]

Heb? and MLR "You're a better man than I am, Gunga Din."

[tacticalogic]

Therefore, I have every confidence that they were acting in that situation as God would have them do. It is interesting, I think, to note that there has never been much if any reconsideration of their basic position--that is, few if any have said they were wrong in their approach.

In your opinion, would that situation be substantially different if they had lost? Thankfully, we will never know for sure, but your post illustrates one critical point. While God's will and His truth are perfect and absolute, our understanding of them is much less so. Then, as now, christian men of good faith disagreed over the affairs and foibles of men, both sides convinced that they were being true to His word.

[tacticalogic]

I pray America never gets to that point, where every hungry soul has his fill of this society crippling vice.

And I pray that we do get there, and find that our fill is little more than a curious nibble.

[aristeides]

The prohibition of alcohol ended in 1933, when drastically reduced tax revenues created a need to find a new source of tax revenue.

State tax revenues are currently badly depressed. I think taxing marijuana might give the states a lot of new revenue.

[monkey]

I was asking specifically about your earlier comment: "if intoxicants including marijuana are more freely available, they will simply add to the use of hard drugs, among those who are so inclined".

The authors are saying that they can't tell if there would be more hard drug use if marijuana were more/less available.

Suppose, for example, that 100 individuals are prone to use drugs, starting with marijuana. 5 go on to use heroin. If marijuana were not available, but heroin was, would more than 5 start with heroin? Or would the same 5 use heroin, or less than 5? The study says, basically, they don't know. It's a very hard thing to figure out, because the potential underlying variable that they mention (proneness to using soft or hard drugs) is difficult to quantify.

[tpaine]

tpaine:
"I think you should come up with a controversial title..."

How about "Totalibertarian Manifesto" ? ;^)
103 headsonpikes

That term certainly makes sense to the "totally-unspun-roscoetarians" among us.

[tpaine]

"The basic principles of economics and marketing are borne out, in either case. Boiling it down to one short sentence:
The more drugs are available on the market, the more use there will be of a greater variety of drugs."


So what? -- The problem society faces comes from the substance ~abuse~ behaviors of individuals, not from the type of substance used. Use & abuse are not the same.
-- You prohibitionists are trying to alter human nature by prohibitions on goods, an impossible task, contrary to constitutional principles.

Attempts to control 'vice' with law only corrupt the legal system, as was evident with booze prohibition.
Its time to stop the WOD charade, and let states regulate the trade. Then we will see whether the "basic principles of economics and marketing are borne out".
They will be, and the rational rule of law will return to our republic.

[Hebrews 11:6]

...when the Bible speaks of "civil authority," as it pertains to America, it means first the Sovereign People, first.

Can't agree. It is quite clear from the context that we are mandated to submit to dictatorships as much as democracies, at least to the extent that their laws do not contradict God's, which of course is the point. "Romans" was written first of all to those living under the authority of Rome's iron fist.

We are the highest ranking authority in our land (and we elect and appoint public servants by o-u-r constitutions).

True, and we have several means to rise up to protest unjust laws. Unless they violate God's law, though, we are bound to obey them.

[Hebrews 11:6]

would that situation be substantially different if they had lost?

Would history treat them as kindly? Of course not, but then popularity does not measure justice. In the end, you do what you deem right, and if you're smart you reach that decision by consulting God first, in His Bible, through prayer, and through the counsel of His godly people. Then you act, prepared for the consequences.

[FastCoyote]

"I'm not paranoid, friend. My point is simply that using these drugs is illegal. Therefore, anyone using them is committing a crime. Got it? "

A crime against what? Against God? I don't see anything in the bible against moderate use of drugs. A crime against the government? I don't see one mention of drug laws in the constitution.

[TigersEye]

Other Scriptures add that where there is a conflict between their civil law and God's law, then that is an inherently un-good law, and we must instead obey God's law.

Scripture admonishes to render unto Caesar what is Caesar's. Did Caesar give us the herbs of the field or fruits of the vine and orchard?

[Hebrews 11:6]

Since you don't see, I won't paint the picture.

[Hebrews 11:6]

Romans 13 says Caesar gets to decide what to do with them.

[unspun]

Thanks; I'd just remind that I said "as it pertains to America...." That is, in America, the People are Caesar, unlike the dictators of Rome, etc. Here, we all are the sovereign authority, not just someone(s) with official titles working in some stone buildings, somewhere.

(And contrary to Totalibertarian revisionism, the People have constitutionally authorized ways of prohibiting people at large from possessing very harmful substances, as we choose.)