Memorandum submitted by Baroness Greenfield
I shall limit my comments to those within my
area of expertise, neuropharmacology. Although I am concerned
by the effects of drugs on the body as a whole, my specific concern
relates to the actions of drugs within the brain. Moreover, my
views are based not so much on the question of ill-health and
death, but rather on the changes in outlook that can occur with
drugs. I believe that a society composed of citizens who, even
if not physically at peril are, nonetheless over or under-stimulated
because of drugs, would not constitute a desirable society.
In order to explore how drugs in general might
change the mind, it is important to set to one side the differences
in their chemistry and, indeed, the chemical systems they target.
With the probable exception of alcohol, all drugs work on one
or more types of "transmitter" systems in the brain:
they do so by modifying the availability, disposal or molecular
target (receptor) of the transmitters in question. Alcohol works
less specifically on the general propagation of electrical impulses
within neurons, although there is some evidence that it may work
in close conjunction with some transmitter systems rather than
Although the action of the transmitters themselves
is short-lived, repeated neurotransmission changes the connections
on a more permanent basis. Repeated use of a synapse will "strengthen"
it. We now know that this change in the efficiency of the synapse
is caused by changes within the brain cell, via genes that can
change the proteins and even the shape of the target neuron. Another
long-term change is that if the receptors ("targets"
for transmitters) are over-stimulated, they become less sensitive,
rather like a handshake where the hand becomes increasingly numb
if continuous pressure is applied. We know that this "desensitisation"
of receptors, is one of the factors in addiction. Hence, "modification"
of transmitter systems may have serious and long-lasting effects
on the brain, and hence on the way we see the world.
Although we are born with more or less all the
brain cells we will ever have, it is the growth of the connections
between these brain cells that accounts for the growth of the
brain after birth. These connections will mirror individual experiences,
even if one is a "clone", ie an identical twin! I have
suggested that it is the plasticity of the brain, its personalisation
through experience, that could be regarded as the "mind"
(Private Life of the Brain, Penguin 2000). Moreover, not
only does the mind evolve as these connections are gradually forged
as a result of our experiences, but this "plasticity"
continues throughout life. Hence we are seeing the world endlessly
updated in the light of our previous experiences.
If drugs work on the connections that in turn
act as a physical basis for the way we evaluate people, objects
and events, then it is easy to see how these same chemicals could
literally change or even "blow" the mind. Clearly, the
severity of the drugs are classified legally according to how
dangerous they are in terms of health, and the risk of death.
But my own view is that all drugs should be regarded as dangerous,
in that they have the power to modify the mind long-term. Indeed,
it is hard to see how drugs could not have these actions, given
their effects on mood and, allegedly in some cases, on pain relief.
Hence the arguments articulated for cannabis in the enclosed document,
written for The Project Syndicate in Sweden (An Association of
Newspapers Around the World) may also be extended in principle
to drugs such as Ecstasy, cocaine, heroin and amphetamine.
The single important point I wish to emphasise
is that it is not as if the individual is an inviolate entity,
separate from his or her experiences. Anyone who takes drugs will
run the risk of changing their personality and their view of the
Such arguments would indeed extend to prescribed
as well as proscribed drugs. It is simply that for medicinal reasons
the cost benefit analysis is more justified.
In my view, there are three general areas that
have received insufficient attention in considering how to deal
with drugs and society:
improving education in how drugs
work in the brain. Although the brain is considered a technical
subject, I have myself spoken to 11 and 12 year olds, about the
broad way in which drugs work on transmitters, and have had very
favourable and grateful feedback from children and parents. Indeed,
I have also spoken at Brixton prison, at the invitation of the
inmates, who were concerned over drug-related crime. They had
no idea of how drugs worked on the brain and appeared, at least,
to be fascinated;
more neuroscientific research into
areas of contentious debate concerning relative doses of alcohol,
cannabis and other drugs, on brain cell viability; and
more initiatives exploring the real
motives as to why people take drugs, eg peer-pressure, a desire
to seek oblivion, or the need for some new type of experience.
Such projects would involve a vast range of
different constituencies from schools, the media, and social services.
Psychologists and neuroscientists could also make a valuable contribution
in exploring what is happening in the brain when someone takes
drugs, and how such experiences are analogous to non-drug taking,
but pleasurable scenarios (see Private Life of the Brain
In summary, a softening of the laws on drugs,
including decriminalisation, would be sending out signals to society,
especially to young people, that drugs are not really harmful
and, perhaps even more importantly, that this is an answer to
the problems of life.