Advisory
Council on the Misuse of Drugs - The
classification of cannabis under the Misuse of
Drugs Act 1971
4.3.5 Unlike
sedative intoxicants such as alcohol, cannabis
does not cause respiratory depression or suppress
the gag reflex even when extremely intoxicated.
4.3.6 Cannabis
differs from alcohol, however, in one major
respect: it seems not to increase risk-taking
behaviour. This may explain why it appears to
play a smaller role than alcohol in road traffic
accidents. … cannabis rarely contributes to
violence either to others or to oneself, whereas
alcohol use is a major factor in deliberate
self-harm, domestic accidents and violence.
4.4.1 In general
cannabis users smoke fewer cigarettes per day
than tobacco smokers and most give up in their
30s, so limiting the long-term exposure that we
now know is the critical factor in
cigarette-induced lung cancer.
4.4.5 It is
possible to rank the risks of dependence of
abused drugs with heroin and crack cocaine the
worst and cannabis generally at, or near, the
bottom (and well below nicotine and alcohol).
4.5.1 Tobacco
smoking and alcohol use are significant causes of
harm to the unborn child. Cannabis may also
increase the risk of minor birth defects and
abortion but the effect is small.
4.5.2 There is
some evidence that smoking cannabis during
pregnancy may produce subtle alterations in
neuropsychological performance of the child that
persists into later life. This effect is similar
to that of tobacco smoking and may be due to the
actions of tobacco smoke rather than to cannabis
per se.
4.5.3 Taken
together this data suggest that cannabis use in
pregnancy is not safe but that it is probably no
more dangerous to the foetus than either alcohol
or tobacco.
4.6.3
Interestingly, other studies have found that the
use of alcohol and tobacco in early teens (and
especially in pre-adolescents) appears to be
associated with the later use of many drugs
including cannabis.
4.6.4 Despite
all these caveats, it is likely that cannabis use
(and that of alcohol or tobacco) has an effect on
later Class A drug use.
4.7.1 Cannabis
appears not to make as major a contribution to
road traffic or other accidents as alcohol.
5.1 The high use
of cannabis is not associated with major health
problems for the individual or society.
5.2 The
occasional use of cannabis is only rarely
associated with significant problems in otherwise
healthy individuals. These harmful effects of
cannabis, however, are very substantially less
than those associated with similar use of other
drugs, such as amphetamines, which (like
cannabis) are currently classified as Class B.
5.4 Regular
heavy use of cannabis can result in dependence,
but its dependence potential is substantially
less than that of other Class B drugs such as
amphetamines or, indeed, that of tobacco or
alcohol.
5.5 It is not
possible to state, with certainty, whether or not
cannabis use predisposes to dependence on Class A
drugs such as heroin or crack cocaine.
Nevertheless the risks (if any) are small and
less than those associated with the use of
tobacco or alcohol.
6.1 Cannabis is
not a harmless substance and its use
unquestionably poses risks both to individual
health and to society.
6.2 Cannabis,
however, is less harmful than other substances
(amphetamines, barbiturates, codeine-like
compounds) within Class B of Schedule 2 to the
Misuse of Drugs Act 1971. The continuing
juxtaposition of cannabis with these more harmful
Class B drugs erroneously (and dangerously)
suggests that their harmful effects are
equivalent. This may lead to the belief, amongst
cannabis users, that if they have had no harmful
effects from cannabis then other Class B
substances will be equally safe.
6.3 The Council
therefore recommends the reclassification of all
cannabis preparations to Class C under the Misuse
of Drugs Act 1971.