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

[rb22982]

No idea, just basing it on the actual physical properties of the drug, not hearsay.

[bigfootbob]

"Tomorrow, I'll be coming after you, but at this moment my bride is calling me for dinner. ;^)"

HAHAHA, this from someone who lives in the marijuana capital of the West coast.

[unspun]

We don't need to be at war on this; we just need to act wisely and responsibly.

But, do you mean this kind of posting for instance? -- a response to a post from an apparent drug libber, who presented this standard for prohibiting legislation about matters that are... "above and beyond living peacefully and honestly."

A Libertarian standard would interpret this only as if it said "legislate only against the immediate, direct, and objective infringement upon the peace of others." An intellectually honest view, however is that traditionally, this does not satisfy free Americans who have always sought to promote the general welfare through responsible government action, from guardrails on highways, to banning intoxicants, to investing in vaccines, to outlawing sex with consenting minors, to banning the unauthorized ownership of deadly contagens, to prohibiting consentual fights to the death (even in dogfight events) to banning unauthorized tests of nuclear fission, and on and on.

Americans have been at work, choosing very carefully, from the get go, what negative behaviors to legislate, which lead to and result in the violation of our peace or freedom, and the deterioration of our welfare. We weigh these things in the balance. It is fundamentally dishonest to engage in destructive behaviors of all sorts and free, republican Ameicans have traditionaly treated these matters with liberties of all sorts in mind. In mind in good perspective, that is.

Any judge or justice worth his salt has understood this, with the very balance of consideration declared in the Preamble to the Constitution, its summarizing statement of original intent.

But I understand that this is "statism" and "socialism" to revisionistic Libertarians. Not to worry; I understand that. But the sovereign People do not need to be forced to exhalt the regard of our rights and liberties above our mutual responsibilities so as to disconnect the two. We do not need to be imposed upon to idolize liberties.

[yendu bwam]

I.e., either way you slice it, if intoxicants including marijuana are more freely available, they will simply add to the use of hard drugs, among those who are so inclined.

You hit the nail on the head. Thank you.

[unspun]

Oh come on. I tried hemp flavored food at the local "health food" store and it tasted like, well... "Why do you think they call it sh!#?"

I don't think heads' (no druggie allusion sought) would wanna eat that stuff. ;-`

Need to feed that habit, myself.

[Hebrews 11:6]

Exactly. Do you speed?

[Hebrews 11:6]

Get serious. The proportionality I cited--marijuana to hard drugs--is much closer than your ridiculously extreme examples. I reiterate--if you're willing to break the law, either the criminal law or that of self-preservation, in a relatively minor way, you're probably ready to break it in a big way. Perhaps that's why Jesus pointed out that he who is willing to be faithful in little things can be trusted with bigger ones.

[eno_]

Nobody is calling you a liar. Your statement is just not very likely. It's a bit like someone claiming Tylenol made them rape and kill, or a Twinkie (oops, never mind...).

[Hebrews 11:6]

Keeping MJ illegal encourages the use of hard drugs.

What do you suppose criminalizing marijuana use does to encourage marijuana use? Would consumption go up or down if it were legalized? Has it? What is the observed effect on hard drug use?

[superfluousdude]

Cannabis linked to Biblical Healing
http://news.bbc.co.uk/2/hi/health/2633187.stm
It's a miracle! The sick are well again... and stoned!

"Weed is from the Earth. God put this here for me and you."
- from the movie Friday

[bigfootbob]

Here's a fact that should get all the WOD lovers foaming at the mouth. Since the medical marijuana law in California was enacted in 1996, marijuana has been and is used as a "Gateway Drug Back", nifty term, Eh?

That is a clinical term used for the substitution of cannabis for more HARMFUL drugs-especially alcohol and opiates. Harm reduction. Cannabis is used for the dextoxification of alcoholics and opiate dependency.

Don't believe me? Look for yourself: http:/www.mikuriya.com/meduses.html

Dr. Mikuriya, MD, is a renowned Psychiatrist, specializing in alcohol and drug dependency, and a retired 2nd Lt Army Medical Corp.

[sinclair]

What is this marijuana stuff I keep hearing about here?

GET MY ROCKS OFF

Some men need some killer weed
and some men need cocaine.
Some men need some cactus juice
to purify their brain.
Some man need 2 women,
and some need alcohol.
Everybody needs a little something
but, Lord, I need it all...

To get my rocks off, get my rocks off,
get my rocks off the mountain...
and roll'em down the hill.

I may do you one time
and I may do you more
And I may turn you in to somethin'
you ain't ready for.
I might want your body
or I might want your bread
Or I might want your Momma
to come visit me instead...

To get my rocks off, get my rocks off,
get my rocks off the mountain...
and roll'em down the hill.

Sometimes I dream of chicks
to bring me everlasting joy.
Sometimes I dream of animals,
sometimes I dream of boys.
Sometimes I kill the living,
sometimes I raise the dead.
Sometimes I just say screw it all
and jump back into bed...

And get my rocks off...
To get my rocks off, get my rocks off,
get my rocks off the mountain...
and roll'em down the hill.

SHEL SILVERSTEIN

[Mike4Freedom]

Would consumption go up or down if it were legalized?

Let us assume that MJ were legalized and treated like alcohol is now. It would be made into cigarettes in legal factories with quality control systems so there would be consistent dosage and no unknown additives. It will probably be sold side by side with alcohol in what are now called liquor stores.

Kids would have a hard time getting any, though they might get some. They get some beer now, often with the assistance of their parents.

The government would stop the silly lies about its effects and the people who need it would have no problem getting their medicine. The black market would lose its biggest money maker and MJ smokers would have no need to do business with those guys.

Many lawyers in the prosecution and defense business would be out of work. So would many police, prison guards, testing companies, drug counselors and drug dealers.

Tens of thousands of people would become productive, tax paying citizens again when they are released from jail.

All in all, sounds like a really good idea, whether consumption goes up or down. My guess is that there will be little change, but we will never know for sure since we have no accurate numbers on use now, since it is all black market.

[Karsus]

What is your opinion of strong drink?


What you just said:

"I reiterate--if you're willing to break the law, either the criminal law or that of self-preservation, in a relatively minor way, you're probably ready to break it in a big way"


Your broad, unsupported statement says that if you break ANY minor law you will more than likely break a major law. Do not blame me for what you type.

[Karsus]

Easy. Because it is forbidden, just look at teens and beer. Just like the rate of rape is lower in countries that have less restrictive rules on pornograpy and prostitution.

[rb22982]

The 1999 federal National Household Survey of Drug Abuse provides an estimate of the age of first use of drugs. According to the Household Survey, the mean age of first use of marijuana in the US in 1997 was 17.2 years. The mean age of first use of alcohol in that year, on the other hand, was 16.1 years, and the mean age of first use of cigarettes was 15.4 years old.

Source: Substance Abuse and Mental Health Services Administration, US Department of Health and Human Services, Summary of Findings from the 1999 National Household Survey on Drug Abuse (Rockville, MD: SAMHSA, August 2000), pp. G-49, G-60 & G-61.

Over 72 million Americans have used marijuana, yet for every 120 people who have ever tried marijuana, there is only one active, regular user of cocaine.

Source: Substance Abuse and Mental Health Services Administration, US Department of Health and Human Services, National Household Survey on Drug Abuse: Population Estimates 1998 (Washington DC: US Department of Health and Human Services, 1999), pp. 19, 25, 31.

Substance	Ever Used	Used in Past Year	Used in Past Month	Number of Frequent Users
Alcohol	184.4 million 81.7%	143.6 million 63.7%	109.0 million 48.3%	46.3 million 20.5%
Tobacco	161.0 million 71.4%	78.6 million 34.8%	66.4 million 29.5%	N/A
Marijuana	83.2 million 36.9%	21.0 million 9.3%	12.1 million 4.8%	N/a
Cocaine	27.7 million 12.3%	4.1 million  1.9%	1.6 million 0.7%	N/A
Crack	6.2 million 2.8%	1.0 0.3%	0.4 0.2%	* N/A
Heroin	3.0 million 1.4%	0.45 0.2%	0.12 0.1%	* N/A

Source: Substance Abuse and Mental Health Services Administration, US Department of Health and Human Services, Results from the 2001 National Household Survey on Drug Abuse: Volume 1. Summary of National Findings (Rockville, MD: Ofice of Applied Studies, August 2002), p. 109, Table H.1; p. 110, Table H.2; p. 129, Table H.21; and p. 130, Table H.22.

Sorry, not much of a correlation

[unspun]

A friend of mine tried marijuana once. It made him want to rape and kill.

And you have no right to keep him from feeling that way!
/sarc

[unspun]

Obviously the anthem of an enlightened soul and an objective mind. ;-` A strong conservative who wants to conserve as much liberty as he possibly can.

[unspun]

Easy. Because it is forbidden, just look at teens and beer. Just like the rate of rape is lower in countries that have less restrictive rules on pornograpy and prostitution.

We should legalize murder, to reduce the thrill of it all. It would save so many lives.

[unspun]

If you want the numbers to go up for drugs, release them to the free market system.