Eating Disorders and the Brain

255 Pages·2011·3.764 MB·English

by  Bryan Lask, Ian Frampton

Eating Disorders and the Brain
Eating Disorders
and the Brain
Edited by
Bryan Lask
Regional Eating Disorders Service, Oslo, Norway
Ellern Mede Service for Eating Disorders, London, UK
Great Ormond Street Hospital for Children, London, UK
Ian Frampton
University of Exeter, Exeter, UK
Regional Eating Disorders Service, Oslo, Norway
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LibraryofCongressCataloging-in-PublicationData
Eatingdisordersandthebrain/[editedby]BryanLaskandIanFrampton. – 1sted.
p.;cm.
Includesbibliographicalreferencesandindex.
ISBN978-0-470-67003-3 (cloth:alk.paper) – ISBN978-1-119-99843-3 (ePDF) – ISBN978-1-119-97364-5
(ePub) – ISBN978-1-119-99840-2(Wileyonlinelibrary) – ISBN978-1-119-97365-2(mobi)
1.Eatingdisorders–Pathophysiology.2.Brain–Pathophysiology.I.Lask,Bryan.II.Frampton,Ian.
[DNLM:1.EatingDisorders–physiopathology.2.EatingDisorders–psychology.3.Brain–physiopathology.
4.Neurosciences.WM175]
RC552.E18E282572011
616.85(cid:2)26–dc22
2011006757
AcataloguerecordforthisbookisavailablefromtheBritishLibrary.
Thisbookispublishedinthefollowingelectronicformats:ePDF9781119998433;ePub9781119973645;Wiley
OnlineLibrary9781119998402;Mobi9781119973652
Setin10/12ptTimesbyLaserwordsPrivateLimited,Chennai,India
First2011
Coverdesignbasedonanillustration©AnaRibeiro
Bryan dedicates this book to Ana.
Ian dedicates this book to Katie, Ellie and Merryn.
Contents
Preface xi
List of contributors xiii
Acknowledgements xv
1 Why clinicians should love neuroscience: the clinical relevance
of contemporary knowledge 1
DavidWood
1.1 Introduction 1
1.2 The legacyof mind–bodydualism 2
1.3 Free willand determinism 3
1.4 Clinicalimplications 3
1.5 Restrictionofenergy intakeand increaseinenergy output 4
1.6 Non-eating-relatedconcerns 5
1.7 In-the-beginningquestions:theproblemofaetiologyineatingdisorders 6
1.8 The temporal,‘vertical’aetiologicaldimension 7
1.9 The spatial,‘horizontal’aetiologicaldimension 11
1.10 The importanceofaneuroscientificaetiologicalframework 13
1.11 Conclusion 15
References 16
2 Eating disorders: an overview 19
BethWatkins
2.1 Introduction 19
2.2 Clinicaldescriptions 20
2.3 Comorbidity 24
2.4 Epidemiology 25
2.5 Aetiologyandriskfactors 27
2.6 Treatment 35
2.7 Courseand outcome 40
viii Contents
2.8 Conclusion 41
References 41
3 Neuroimaging 56
ToneSeimFuglsetandIanFrampton
3.1 Introduction 56
3.2 Structuralimaging 56
3.3 Functionalimaging 90
3.4 Conclusion 101
References 101
4 Neuropsychology 106
JoannaE.SteinglassandDeborahR.Glasofer
4.1 Introduction 106
4.2 Intellectualfunctioning 107
4.3 Attention 108
4.4 Memory 110
4.5 Visuospatialprocessing 111
4.6 Executivefunctioning 113
4.7 Conclusion 116
References 117
5 Neurochemistry: the fabric of life and the fabric
of eating disorders 122
KennethNunn
5.1 Introduction 122
5.2 Fiveaims 122
5.3 Fivepropositionsrelatingneurochemistrytothefield
ofeatingdisorders 123
5.4 Fiveimplicationsofthesepropositions 127
5.5 Fivedirectionsfor futureresearch 127
5.6 Conclusion 127
Acknowledgement 128
References 128
6 Body-image disturbance 129
MariaØvera˚s
6.1 Introduction 129
6.2 Whatisbodyimage? 130
6.3 Howisbodyimageconstructedinthebrain? 130
6.4 Body-imagedisturbanceineatingdisorders 133
6.5 Theneuroscienceofbody-imagedistortioninanorexianervosa 134
6.6 Conclusion 138
References 139
Contents ix
7 Conceptual models 142
MarkRoseandIanFrampton
7.1 Introduction 142
7.2 Conceptualmodelsinanorexianervosa 143
7.3 Conclusion 161
References 163
8 Towards a comprehensive, causal and explanatory neuroscience
model of anorexia nervosa 164
KennethNunn,BryanLaskandIanFrampton
8.1 Introduction 164
8.2 The model 164
8.3 Criticalappraisal 173
8.4 Clinicalimplications 175
8.5 Conclusion 177
Acknowledgements 177
References 177
9 Neurobiological models: implications for patients and families 180
IlinaSinghandAlinaWengaard
9.1 Introduction 180
9.2 The emergence ofneurobiologicalmodels 180
9.3 Anorexianervosaandillnessrepresentations 181
9.4 Impact ofa neurobiologicalmodel onfamilies’understandings
of anorexianervosa 183
9.5 Conclusion 188
References 189
10 Implications for treatment 191
CamillaLindvallandBryanLask
10.1 Introduction 191
10.2 Psychopharmacology 192
10.3 The educationalcontext 193
10.4 Psychologicaltreatment 194
10.5 Conclusion 205
References 205
11 Future directions 207
IanFramptonandBryanLask
11.1 Introduction 207
11.2 Cause 207
11.3 Assessment anddiagnosis 208
11.4 Treatment 210
x Contents
11.5 Prevention 211
11.6 Futuredirections 212
11.7 Conclusion 215
References 216
Index 219
Preface
Bryan Lask and Ian Frampton
The human brain is often described as ‘the most complex structure in the universe,
too complex for the human brain to understand’ – a most delightful paradox. Eat-
ing disorders too are extraordinarily complex, difficult to understand, demanding to
treat, have a poor prognosis and are themselves full of paradox. Surely then a union
between these two unlikely bedfellows, as attempted in this book, cannot be an easy
task? And perhaps this is why there have been relatively few such attempts to date.
Yet, despite decades of effort, enormous amounts of research money and well over
100000 publications, we still do not have an adequate understanding of the patho-
genesis of eating disorders! We are still unable to explain why any one individual
develops an eating disorder, while the majority do not, and we still do not have
effective treatments. Until relatively recently, sociocultural attempts to elucidate the
developmentofeatingdisordershavebeenthemostinfluential.However,whileoffer-
ingapart-explanation,theyhaveprovedinsufficientinaccountingfortheveryspecific
phenomena so characteristic of these conditions.
Inrecentyears,toanextentperhapsinspiredbythe‘decadeofthebrain’,therehas
been more of a focus on what neuroscience might contribute to our understanding.
Andtheresultshavebeenenlightening.Forexample,neuropsychologicalstudieshave
shownimpairmentsindifferentcognitivefunctions,especiallyexecutiveandvisuospa-
tialskills,whichappeartobetrait-ratherthanstate-related;inotherwords,theyseem
to predate the onsetandtherefore mayactually be riskfactors for the developmentof
aneatingdisorder.Structural(anatomical)neuroimagingstudiesshowcorticalatrophy
and ventricular enlargement, which do indeed reverse with refeeding and are there-
forelikelytobesecondarytoinadequatenutrition.However,functionalneuroimaging
consistently reveals regional and asymmetrical reduction in blood flow, suggesting
dysfunction in specific brain regions, which is unlikely to be due simply to starva-
tion and suggests regional dysfunction. This too may be a predisposing factor or a
reflection of one. Neurochemistry studies show dysregulation within neurotransmitter
xii Preface
systems, with effects upon the modulation of feeding, mood, anxiety, neuroendocrine
control, metabolic rate, sympathetic tone and temperature. These studies indicate that
neural mechanisms have a fundamental role in the origin and maintenance of the dis-
orders. Thus we now have far more detailed information on the effects on the brain
of starvation, overeating, chaotic eating and dehydration. Even more importantly, we
now understand far more about the underlying brain abnormalities and dysfunctions
that may contribute to the development of these serious disorders.
In this book we explore in depth how neuroscience knowledge informs our under-
standing of eating disorders and how it may be applied in clinical practice. We may
haveerredbyfocusingrathermoreonanorexianervosa(AN)thantheothereatingdis-
orders,buthopetobeforgiven,becausethereismoreneuroscience-basedinformation
availableonthiscondition.Thefirstchapter,byclinicianDavidWood,offersaninvi-
tationtofellowclinicianstobecomeacquaintedwiththeseeminglyscary,butactually
fascinating, world of neuroscience, as applied to eating disorders. In Chapter 2, Beth
Watkins provides a meticulous review of the eating disorders – most of the infor-
mation anyone is likely to need is contained therein. The next three chapters review
in detail contemporary knowledge of neuroimaging (Tone Fugslet and Ian Framp-
ton), neuropsychology (Joanna Steinglass and Deborah Glasofer) and neurochemistry
and genetics (Ken Nunn). In Chapter 6, Maria Øvera˚s explores how neuroscience
contributestoourunderstandingofoneofthecorefeaturesofeatingdisorders,body-
imagedisturbance.MarkRoseandIanFrampton, inChapter7,explore andcomment
upon a number of neuroscience-based conceptual models of eating disorders. Each
advances our understanding to some extent but none offers a full explanation of the
pathogenesis, phenomenology and maintenance of any of the eating disorders. In
Chapter 8, Ken Nunn, Ian Frampton and Bryan Lask attempt the seemingly impossi-
ble and propose just sucha model for AN. It is for the reader, and subsequenttesting
of the model, to decide whether or not they have succeeded. The next two chapters
exploretheclinicalrelevanceofneuroscienceknowledge:IlinaSinghandAlinaWen-
gaard (Chapter 9) consider the consequences of the development of neurobiological
models for the understanding of eating disorders by patients and their families and
their receptivity to treatment. Camilla Lindvall and Bryan Lask (Chapter 10) explore
how this empirical knowledge can be converted into practice, with emphasis on its
application in both an educational and a clinical context. In relation to the latter they
offeraspecificfocusoncognitiveremediationtherapy.Inthefinalchapter,theeditors
offer a summary of the contents of the previous chapters and explore how these find-
ings might be investigated in the future, considering in turn each of the US National
Institute of Mental Health Research Domain Criteria (RDoC) Project classes: genes,
molecules, cells, neural circuits, behaviours and self-reports.
Wehopethatthis volumewill takeusa smallstepforwardinourunderstandingof
theneuroscienceofeatingdisordersandwillopenupanexcitingandrelevantavenue
for all of its readers, regardless of their previous knowledge in the field.