Brain science, addiction and drugs

220 Pages·2008·1.24 MB·English

Brain science, addiction and drugs
An Academy of Medical Sciences working group report
chaired by Professor Sir Gabriel Horn FRS FRCP
May 2008
The Academy of Medical Sciences
The Academy of Medical Sciences promotes advances in medical science and campaigns to ensure
these are converted into healthcare benefits for society. Our Fellows are the UK’s leading medical
scientists from hospitals and general practice, academia, industry and the public service.
The Academy plays a pivotal role in determining the future of medical science in the UK, and
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and capacity building and help to remove barriers to progress.
ISBN No: 1-903401-18-6
Brain science, addiction and drugs
An Academy of Medical Sciences working group report chaired by
Professor Sir Gabriel Horn FRS FRCP

May 2008
BRAin SCienCe, AddiCtion And dRuGS
Acknowledgements and disclaimer
the Academy of Medical Sciences is most grateful to Professor Sir Gabriel Horn FRS FRCP and the
members of the working group for undertaking this important study. We thank the department
of Health and the department for innovation, universities and Skills’ Sciencewise programme for
their generous support of the study. We are also grateful to participants in the public engagement
programme, the office for Public Management and the public engagement contractors, members
of the cross-Government advisory group, the external review group, Academy Council members,
Fellows and staff for their participation, input and support.
this report is published by the Academy of Medical Sciences and has been endorsed by its officers
and Council. Contributions by the working group were made purely in an advisory capacity.
the review group added a further ‘peer-review’ stage of quality control to the process of report
production. Members of the working group and the review group participated in this report in
an individual capacity and not as representatives of, or on behalf of, their affiliated hospitals,
universities, organisations or associations. their participation should not be taken as endorsement
by these bodies.
All web references were accessed in April 2008.
© Academy of Medical Sciences
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helps policy makers commission and use public dialogue to inform policy decisions in emerging
areas of science and technology. it consists of a comprehensive online resource of information,
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For further information please log onto www.sciencewise-erc.org.uk
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ContentS
Contents
Abbreviations 5
Summary 7
Objectives and scope of report 9
Background and objectives 9
Scope 9
Process 10
Review 11
Chapter 1 Introduction 13
1.1 Scientific background 1
1.2 Societal aspects 15
Part I: Recreational Drugs
Chapter 2 Public engagement 17
2.1 Background and objectives 17
2.2 implementation 18
2. Findings 19
2.4 discussion 27
Recommendation 28
Chapter 3 Magnitude of the problem 29
introduction 29
.1 the nature of the problem 29
.2 trends in specific drugs 2
. Future sources of psychoactive substances 5
.4 Measuring the size and scale of drug use 7
Recommendation 41
Chapter 4 Neuroscience, addiction, pharmacology and treatment 43
introduction 4
4.1 neuroscience of addiction 4
4.2 Pharmacology and treatment 51
4. Brain science and future psychological therapies 56
4.4 discussion 59
Recommendations 62
Chapter 5 Harm and regulation 63
introduction 6
5.1 Philosophical principles concerning the regulation of illegal psychoactive substances 6
5.2 Regulatory strategy 66
5. Measuring the harm associated with the use of illegal psychoactive drugs 7
5.4 discussion 88
Recommendations 90

BRAin SCienCe, AddiCtion And dRuGS
Chapter 6 Risk factors and prevention 93
introduction 9
6.1 individual differences 9
6.2 Family social factors 104
6. Societal factors 106
6.4 timing of substance misuse 110
6.5 Protective factors 11
6.6 discussion 114
Recommendations 115
Part II: Medicines for mental health
Chapter 7 Medicines for mental health 117
introduction 117
7.1 Common mood disorders: depression and anxiety 118
7.2 Bipolar (manic-depressive) disorder 121
7. Schizophrenia 122
7.4 Personality disorders 12
7.5 Mental illness in childhood and adolescence 124
7.6 Benefits and limitations of current drugs 126
7.7 Brain sciences and mental health 128
7.8 the development of new curative and preventative treatments 1
7.9 discussion 18
Recommendations 141
Part III: Cognition enhancers
Chapter 8 Cognition enhancers 143
introduction 14
8.1 existing cognition enhancers 147
8.2 Cognition enhancing drugs of the future: theoretical pointers from basic research 152
8. Cognition enhancing drugs of the future: current strategies and indications 15
8.4 ethical and regulatory issues 155
8.5 discussion 157
Recommendations 159
Recommendations 161
Part i: Recreational drugs 161
Part ii: Medicines for mental health 164
Part iii: Cognition enhancers 165
Appendix I Report preparation 167
References 171
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ContentS
Abbreviations
5-Ht 5-Hydroxytryptamine (serotonin)
5-Htt 5-Hydroxytryptamine (serotonin) transporter
ACMd Advisory Council on the Misuse of drugs
Ad Alzheimer’s disease
AdHd Attention-deficit Hyperactivity disorder
ALSPAC Avon Longitudinal Study of Parents and Children
AMPA α-amino--hydroxy-5-methylisoxazole-4-propionic acid
AMRC Association of Medical Research Charities
BAS Behavioural Activation System
BCS British Crime Survey
BiS Behavioural inhibition System
BnF British national Formulary
BZP Benzyl piperazine
cAMP Cyclic Adenosine Monophosphate
CAtie Clinical Antipsychotic trials of intervention effectiveness
CBi Combined Behavioural intervention
CBt Cognitive Behavioural therapy
CoMt Catechol-o-Methyl transferase
CnS Central nervous System
CtC Communities that Care
d2 receptors dopamine 2 receptors
dCSF department for Children, Schools and Families
dHi drug Harm index
dnA deoxyribonucleic acid
dSM diagnostic and Statistical Manual
eCt electro-Convulsive therapy
eeG electro-encephalography
eM experimental Medicine
eMddA european Monitoring Centre for drugs and drug Addiction
ePPe effective Pre-school and Primary education
eu european union
FAS Fetal Alcohol Syndrome
FdA Food and drug Administration (uSA)
fMRi Functional Magnetic Resonance imaging
FSA Food Standards Agency
GABA Gamma-Aminobutyric Acid
GP General Practitioner
GWA Genome-Wide Association
HBV Hepatitis B Virus
HCV Hepatitis C Virus
HiV Human immunodeficiency Virus
HPA Health Protection Agency
idu injecting drug user
ioM institute of Medicine (uSA)
iQ intelligence Quotient
iSd international Statistical Classification of diseases
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BRAin SCienCe, AddiCtion And dRuGS
LSd Lysergic Acid diethylamide
LtP Long term Potentiation
MAo Monoamine oxidase
MdMA Methylenedioxymethamphetamine (ecstasy)
MHRA Medicines and Healthcare Products Regulatory Agency
MRC Medical Research Council
MRi Magnetic Resonance imaging
mRnA Messenger Ribonucleic Acid
MRS Magnetic Resonance Spectroscopy
nMdA n-methyl d-aspartate
nHS national Health Service
niCe national institute for Health and Clinical excellence
nidA national institute for drugs and Addiction (uSA)
niHR national institute for Health Research
nnt number needed to treat
ntASM national treatment Agency for Substance Misuse
ntoRS national treatment outcome Research Study
oCd obsessive Compulsive disorder
oCJS offending Crime and Justice Survey
od overdose death
ondCP office of national drug Control Policy (uSA)
onS office of national Statistics
oPM office for Public Management
oSCHR office for the Strategic Coordination of Health Research
Pdu Problem drug user
Pet Positron emission tomography
PMSu Prime Minister’s Strategy unit
PPRS Pharmaceutical Price Regulation Scheme
PtSd Post-traumatic Stress disorder
R&d Research and development
RnAi Ribonucleic Acid interference
SPet Single-Photon emission tomography
SSRi Selective Serotonin Reuptake inhibitor
Sud Substance use disorder
tCA tricyclic Antidepressant
tMS transcranial Magnetic Stimulation
uKAtt united Kingdom Alcohol treatment trial
WHo World Health organization
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SuMMARY
Summary
understanding how the brain works, how Yet this enhanced understanding appears to
drugs affect the brain’s performance and in turn have had little impact on the development of
affect our behaviour, have been key challenges new treatments for addiction. this situation
of 20th century science. the challenges of the is echoed in the fields of mental health and
21st century will be to deepen this understanding neurodegenerative disease, where there is
and to use current and future knowledge for the an urgent need to translate research findings
benefit of individuals, their families and society. in basic science into new and improved
therapies that not only relieve symptoms,
the use of psychoactive drugs has been a and do so without debilitating side effects,
feature of human society for much of recorded but also cure or prevent the onset of
history. As shown in this report, all indicators established disorders.
point to a continued, and in some cases a
growing, use of psychoactive substances, be Fulfilling this potential will require a greater
they legal or illegal so-called ‘recreational’ prioritisation of research into addiction and
drugs, medicines for mental health, or drugs mental health on the part of Government,
called ‘cognition enhancers’, which can enhance research agencies, industry and the health
brain performance in various ways. the use of and social services. For example, investment
psychoactive drugs brings both benefits and in large-scale genetic and epidemiological
costs: while new drugs to treat mental illness studies is needed to determine the interaction
or neurodegenerative disease are to be between genetic and environmental factors
welcomed, there is a compelling need to reduce associated with substance misuse and mental
the burden of harms associated with drug illness. the full range of brain imaging
misuse and addiction. technologies, such as functional magnetic
resonance imaging (fMRi) and positron
Although many outstanding research emission topography (Pet), must also be
questions remain, major advances in genetics, exploited to identify brain changes associated
neuroscience, pharmacology and psychology with vulnerability, onset and progression to
have already provided far-reaching insights mental disorder or addiction. A more dynamic
into normal and abnormal brain function and and multidisciplinary combination of brain
how mental processes can be impaired and imaging, neuroscience, genetics, experimental
enhanced by psychoactive drugs. in this report medicine and other fields holds real promise
we describe research showing that many for the rapid development of new and better
drugs of abuse, for example cocaine, heroin treatments for addiction and mental illness, but
or amphetamines, can ‘highjack’ certain brain only if research is sufficiently resourced and
processes, leading to dependency and addiction appropriately coordinated.
in some people. there is now evidence that
most addictive drugs act on a common brain in this report we show how research is leading
system and this evidence has given rise to to a more ‘holistic’ view of drug misuse and
several neurobiological theories of addiction addiction, involving medical, genetic and
that are currently under investigation. there neurobiological factors as well as individual
is also a much deeper understanding of the factors and social context. this view has led
brain changes that result from chronic drug some experts to characterise addiction as a
use and the range of factors associated with chronic medical illness or, more specifically, as
vulnerability to drug misuse in children and a chronic relapsing brain disorder. As with all
adults, including genetic, psychological and disorders and illnesses, prevention is better than
environmental influences. cure, and our knowledge of the individual, family
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BRAin SCienCe, AddiCtion And dRuGS
and social factors associated with substance disease. However, these drugs will also
misuse must now be utilised to reduce the be attractive to healthy people for use in
impact of known risk factors and to inform public non-medical contexts, perhaps to help
health interventions. this strategy will require them to pass an exam or to improve their
more reliable information on the prevalence and performance at work, giving rise to complex
harms of legal and illegal psychoactive drug use questions about how such use should be
to formulate appropriate interventions and to regulated.
target resources more effectively. Above all, in
this report we seek to emphasise the importance engagement with the public on issues of brain
of a health-based approach to reducing the science, addiction and drugs has formed a key
harms associated with drug misuse, through component of this report and will be crucial in
providing treatments, identifying risk factors, taking forward policy and regulation in these
formulating preventative measures and areas. the public’s ability to make informed
informing regulatory strategies. choices requires the provision of accurate
and balanced information about the potential
in recent years, improvements in our benefits and harms of psychoactive drugs.
understanding of cognition – internal mental Furthermore, an intelligent and appropriate
processes such as attention, learning and approach to the regulation of psychoactive
memory – have led to the identification of drugs requires deliberative and inclusive
several pharmacological agents that can community debate. Continuing the type of
enhance brain performance. these ‘cognition public engagement activities carried out during
enhancers’ can potentially, for example, this project can better inform regulators,
improve short-term memory or speed of allowing them to work with the grain of public
thought, and could therefore bring significant opinion, and so develop policies that can
benefits to patients with neurodegenerative achieve their desired objectives.
Throughout this report, and in our conclusions and recommendations, we emphasise the
following five key messages:
1. Recent advances in brain science hold the promise of significant practical and therapeutic
outcomes for treating mental illness and addiction. However, additional investment is needed
to ensure that knowledge continues to be advanced and translated into benefits for patients.
2. the formulation of better prevention strategies requires enhanced efforts to understand
and identify the factors that put particular individuals and population groups at risk of
mental illness and drug misuse.
. improvements are needed in our information on the prevalence, duration and type of
recreational drug use in the population, to enable more effective targeting of resources.
4. Regulation and policy require a more sophisticated index of the harms caused by the use
of legal and illegal psychoactive drugs.
5. Regulation and policy around recreational drugs, medicines for mental health and cognition
enhancers must move forward in a way that is informed by advances in research and the
views of the public.
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