The feeling of déja vu
was inescapable. It seemed like every high school health class
I ever slept through was suddenly yawning back at me. “Study
Links Pot Use to Hard Drugs,” “Study Ties Marijuana
to Heroin, Crime,” “Study Proves Pot Smoking Leads
to Hard Drug Use.” Headline writers in the popular press
nationwide appeared to be vying with each other to develop the
most sensational context possible for news reports of an unpublished
study funded by the National Institute on Drug Abuse, which NIDA
Director William Pollin chose to make public at a Senate Subcommittee
on Alcoholism and Drug Abuse hearing October 21.
On the surface, the study seemed
to contain nothing all that new in documenting a greater incidence
of previous marijuana use among hard drug users than among the
general population. Anyone with more than a passing familiarity
with drug abuse treatment and prevention generally accepts as
an article of faith the notion that people who turn into addicts
usually seek out various states of intoxication along the way,
and that one of the most easily accessible states of intoxication
(and thus one of the most frequently used intoxicants) is marijuana.
It’s an exceedingly rare addict (and the figures Dr. Pollin made
public bear this out) who starts with heroin, stays with heroin,
and never deviates from heroin. That just isn’t the way drug
abuse usually works.
Nothing new so far.
But Dr. Pollin didn’t stop there.
He made the additional leap of faith to propose that the study
provides solid evidence to support the “stepping stone”
hypothesis linking marijuana with harder drugs. According to
Pollin, the theory “was rejected prematurely and now needs
In case you’d forgotten, the
“stepping stone” hypothesis was the drug world’s domino
theory, formulated by pot prohibitionists of the 1930s and ’40s
and ’50s and popularized by purveyors of shabby entertainments
like the 1936 anti-marijuana film classic, “Reefer Madness.”
The “stepping stone” hypothesis in its original form
postulated an inexorable progression of addictive behaviors culminating
in total addiction following even occasional use of the “killer
Eventually the hypothesis was
modified to reflect the plain fact that the vast majority of
recreational smokers do not subsequently become involved with
harder drugs. Under the terms of the revised “stepping stone”
hypothesis, marijuana was viewed as triggering addictive behaviors
in some users, but not others, victims apparently determined
through an unspecified bio-chemical psycho-physiological pseudo-scientific
quasi-philosophical process probably patterned after the Calvinist
precept of the predestination of the soul.
But all humor aside, the information,
as presented by Dr. Pollin, raises as many questions about the
study’s design and methodology and the political motivations
of the NIDA director as it answers about correlates of chronic
The study itself was conducted
by Dr. Richard Clayton of the University of Kentucky and involved
2,510 men ranging in age from 20 to 30. Participants were queried
about a number of drug-related behaviors, including use patterns
and frequency, as well as non-drug- related behaviors such as
To no one’s great surprise, the
study showed that less than one percent of those who had never
used marijuana went on to use heroin or cocaine. And similarly
unsurprising was the result showing that 73 percent of all persons
who had smoked pot at least 1,000 times had experimented with
cocaine, and 33 percent with heroin. Dr. Pollin also said the
study revealed “a significant relationship between non-drug-related
criminal activities and marijuana use.” Specifically, he
pointed to the results that showed that while only six percent
of nonusers had committed a breaking and entering offense, 27
percent of those who have smoked marijuana more than 1,000 times
have committed the same offense.
What is the inference that we
are supposed to make? That marijuana leads to harder drugs? Or
that marijuana leads to breaking and entering? If we’re careful,
neither, because neither inference holds water on the basis of
the available evidence.
To cite just one example: If
33 percent of the persons surveyed who smoked pot at least 1,000
times expanded their chemical repertory to include heroin, it
would seem to make excellent sense that a fair number of these
would go on to become addicts and thence to break and enter in
the commission of burglaries in support of their heroin habits.
This would not reflect any causality between marijuana use and
breaking and entering, but between heroin addiction and burglary.
Rather than reflecting anything
approaching causality, as Dr. Pollin would apparently have us
believe, these figures merely represent statistical correlation.
And any first semester statistics student can usually tell you
that correlation does not imply causality And in point of fact,
the figures that Dr. Pollin cited could even be questioned as
representing a true correlation, in the sense that they could
be said to measure the same variable — social deviance — from
different angles, ascribing a causal role to one aspect of that
deviance, namely chronic marijuana use.
The National Organization for
the Reform of Marijuana Laws immediately cried foul at Pollin’s
official resurrection of the “stepping stone” hypothesis,
charging that the NIDA director was “playing politics”
with marijuana “by distorting statistics that are unpublished
and that are inconsistent with past studies.”
According to NORML, Pollin’s
motives were purely political. NORML Political Director George
Farnham alleged that NIDA may be eliminated altogether by the
Reagan administration in 1982 and reminded listeners that there
is “no one more sensationalistic than a bureaucrat in need
of an issue to justify his bureaucratic existence.”
And in a telephone interview
with NORML, Dr. Richard Clayton, who authored the new “stepping
stone” study, indicated that it is marijuana’s illegality,
not some psychoactive property of the drug itself, that leads
to the use of harder drugs. Another piece of common-sense wisdom
casually overlooked was the notion that one of the reasons why
people use harder drugs is that dealers push harder drugs —
because their profitability and addictiveness means more money
over extended periods of time for sellers.
So where does all this leave
the old “stepping stone” hypothesis? From the data
that Dr. Pollin made public, back on the scrap heap of discarded
scientific theory, with all the other wrecks and rejects of history,
including the flat earth theory, the spontaneous generation hypothesis,
and Fudd’s First Law of Peripheral Centrifugality.
And Dr. Pollin’s “premature
rejection” to the contrary, that’s probably where it belongs.