How to prevent cannabis-induced psychological distress . . . in politicians

The Lancet
Volume 363, Issue 9421, 15 May 2004, Pages 1568-1569

Cannabis can cause anxiety, agitation, and anger among
politicians. The consequences of this cannabis-induced
psychological distress syndrome (CIPDS) include overreaction
with respect to legislation and politics and a
lack of distinction between use and misuse of cannabis.
In times of a war against drugs, this distinction might
even be regarded as unpatriotic,1 as irresoluteness in the
face of the enemy. One trend associated with CIPDS
involves taking away the driving licence of people who
drive and are discovered to have inactive tetrahydrocannabinol
metabolites in their urine.2 In a more severe
state of paranoia even medicinal use can be perceived as
a threat to society, since it might “destabilize the societal
norm that drug use is dangerous”,3 ignoring the fact that
many prescription and over-the-counter drugs are
potentially harmful. Exaggerated laws on cannabis made
by anxious individuals could be regarded as a modern
version of the generational conflict.4

Rationality and factuality are needed to calm down
politicians affected by CIPDS. That cannabis might
cause infertility, cancer, cognitive decline, dependency,
traffic accidents, and heart attacks, and that it can lead
to the use of more dangerous drugs, are all arguments
that have been used to justify the war on cannabis.
Drugs can be harmful, whether they are legal or illegal,
but claims about the dangers of cannabis are often
overstated.5,6
One main justification for today’s war on cannabis is
its possible detrimental effect on the mental health and
social wellbeing of adolescents. In this week’s Lancet,
John Macleod and colleagues show that the causal
relation is less certain than often claimed, and point out
several common misunderstandings about the difficulties
encountered when studying drug use, such as the limits
of confounder adjustment. The results of one often-cited
Swedish study,7 for example, indicate a crude odds ratio
of 6·7 for schizophrenia risk at age 26 years in
individuals who used cannabis more than 50 times
before age 18 years. This finding suggests cannabis is an
important contributor to schizophrenia. After adjustment
for several possible confounders, however, the risk
decreased to 3·1, a strong indication of residual confounding—
ie, the presence of factors that would further
reduce the risk if included in the statistical model but
that could not be included because of a lack of data.
Another review8 details the findings of an investigation
into the association between cannabis and psychosis on the basis of five longitudinal studies. The authors
conceded that only one of these studies was able to
record whether prodromal manifestations of schizophrenia
preceded cannabis use. The results of the study9
indicated that “cannabis users at age 18 years had
elevated scores on the schizophrenic symptom scale only
if they had reported psychotic symptoms at 11 years”,8
and that people who used cannabis at age 15 years had a
higher risk for adult schizophreniform disorder at age
26 years even if psychotic symptoms at age 11 years
were controlled for.9 The researchers concluded that
cannabis was a causal factor for psychosis in “vulnerable
youths”.8
There is some reason to believe that cannabis contributes
to psychosocial problems in adolescents and
young adults, and no responsible adult would want
young people to take drugs. There is no question that
this issue is an important candidate for education and
prevention, but there is a fierce debate on the place
repressive measures should have in this context. There is
little reason to believe that criminalisation has had a
strong effect on the extent of cannabis use by young
people.10 Moreover, prohibition itself seems to increase
the harmfulness of drug use and cause social harm.
By stopping all cannabis users from being treated as
criminals, I believe this year’s change by the British
Government of its cannabis law (a declassification from
class B to C) is a sensible attempt to balance the
possible harms caused by cannabis and its prohibition.
The concern expressed by Peter Maguire of the British
Medical Association and others,11 that “the public might
think that reclassification equals safe”, is based on the
wrong assumption that cannabis became illegal because
its use is unsafe and dangerous. Many unsafe activities
are legal, including skiing downhill, having sex, drinking
beer, eating hamburgers, and taking aspirin. Cannabis
did not become illegal because it was shown to be
dangerous but, more likely, because Harry Anslinger,
Commissioner of the US Bureau of Narcotics 1930–62,
and his colleagues needed a new target and battlefield
after the end of alcohol prohibition in 1933. Reputed
dangers, presented in his statements before the US
Senate in 1937,12 were used as a shocking means of
manipulation—eg, “A man under the influence of
marijuana actually decapitated his best friend; and then,
coming out of the effects of the drug, was as horrified as
anyone over what he had done.” The representative of
the American Medical Association strongly opposed the
Marijuana Tax Act of 1937: “To say . . . that the use of
the drug should be prevented by a prohibitive tax, loses
sight of the fact that future investigation may show that
there are substantial medical uses for cannabis.”13
We live in a time in which the unrealistic and
unproductive paradigm of complete abstinence from
drugs is slowly dissipating. Proponents of a drug-free
society find this fact hard to accept, and responsible
politicians and doctors can find achieving an appropriate
position in the debate difficult. However, we must learn
to deal with drugs and their possible dangers without
fear.

I have no conflict of interest to declare.

Franjo Grotenhermen
Nova-Institut GmbH, D-50354 Huerth, Germany
(e-mail: franjo.grotenhermen@nova-institut.de)

1 Wish ED. Preemployment drug screening. JAMA 1990; 264:
2676–77.

2 The Walsh Group. The feasibility of per se drugged driving
legislation: consensus report. http://www.walshgroup.org/FINAL%20CONSENSUS%20with%20inside%20cover%20te...
(accessed Feb 18, 2004).

3 Barthwell A. Marijuana is not medicine. Chicago Tribune Feb 17,
2004.

4 Böllinger L, Quensel S. Drugs and driving: dangerous youth or
anxious adults? J Drug Issues 2002; 32: 553–66.

5 Grotenhermen F. Review of unwanted effetcs of cannabis and
THC. In: Grotenhermen F, Russo E, eds. Cannabis and
cannabinoids: pharmacology, toxicology, and therapeutic
potential. Binghamton: Haworth Press, 2002: 233–47.

6 House of Lords Select Committee on Science and Technology.
Cannabis: the scientific and medical evidence. London: HM
Stationery Office, 1998.

7 Zammit S, Allebeck P, Andreasson S, Lundberg I, Lewis G.
Self reported cannabis use as a risk factor for schizophrenia in
Swedish conscripts of 1969: historical cohort study. BMJ 2002;
325: 1199.

8 Arseneault L, Cannon M, Witton J, Murray RM. Causal association
between cannabis and psychosis: examination of the evidence.
Br J Psychiatry 2004; 184: 110–17.

9 Arseneault L, Cannon M, Poulton R, Murray R, Caspi A,
Moffitt TE. Cannabis use in adolescence and risk for adult
psychosis: longitudinal prospective study. BMJ 2002; 325:
1212–13.

10 Williams J. The effects of price and policy on marijuana use: what
can be learned from the Australian experience? Health Econ 2004;
13: 123–37.

11 Anon. Physicians say UK cannabis reclassification may endanger
public health. Reuters Health Information, Jan 21, 2004.

12 Anslinger H. Testimony to Congress during the hearings to the
The Marijuana Tax Act (HR 6385) on April 27–30 and May 4,
1937. http://www.druglibrary.org/schaffer/hemp/taxact/anslng1.htm
(accessed April 14, 2004).

13 Woodward WC. Testimony to Congress during the hearings to
the The Marijuana Tax Act on May 4, 1937. http://www.
druglibrary. org/schaffer/hemp/taxact/woodward.htm (accessed
April 14, 2004).