Behavioral Neurobiology of Eating Disorders (eBook)

Behavioral Neurobiology of Eating Disorders 3
Preface 5
Contents 7
Contributors 9
Part I: Cognition and Emotionsin Eating Disorders 15
Personality and Temperament 16
1 Unique Challenges in the Assessment of Personality and Temperament in the Field of Eating Disorders 17
2 Models and Methodology to Examine the Relationship Between Personality and Eating Disorders 18
3 Current Knowledge Regarding the Relationship of Personality and Temperament and Eating Disorders 20
4 Using Personality and Temperament for Classification and the Search for Genetic Susceptibility Loci 23
5 Conclusions and Future Directions 25
References 26
Cognitions and Emotions in Eating Disorders 30
1 Introduction 31
2 Cognitive Biases 31
2.1 Attention Bias 32
2.1.1 Stroop Task 32
2.1.2 Dot-Probe Task 33
2.1.3 Visual Search Task 34
2.1.4 Eye Tracking 35
2.2 Interpretation Bias 36
2.3 Memory Bias 37
2.3.1 Explicit Memory Bias 37
2.3.2 Implicit Memory Bias 38
3 General Impairments in Cognitive Processing 38
3.1 Set Shifting 38
3.2 Central Coherence 39
3.3 Decision Making 39
4 Manipulation of Cognitive Processes 40
4.1 Retraining Attention Bias 40
4.2 Modulation of Food Reward Processing 41
5 Cognitive Therapy 42
References 43
Part II: Neural Circuits, Neurotransmitters,and Behavior 47
Neurocircuity of Eating Disorders 48
1 Introduction 49
1.1 Confounding Effects of Malnutrition 50
1.2 Vulnerabilities That Create a Risk for Developing AN and BN 50
1.3 Recovered (REC) AN and BN Subjects 50
1.4 Persistent Alterations in ED Found in Brain Imaging Studies After Recovery 51
1.5 Implications 52
2 Appetitive Regulation and AN and BN 52
2.1 Studies of Altered Feeding Behavior in AN and BN 52
2.2 Brain Imaging Studies of Feeding Behavior in AN and BN Confirm Alterations in Limbic and Cognitive Circuits 53
2.3 Neurocircuitry of Appetite Regulation 53
2.4 Gustatory fMRI Studies 55
2.5 Implication 56
3 Does the Anterior Insula Contribute to Altered Interoceptive Awareness in AN? 56
4 Reward Function in AN and BN 57
4.1 Altered DA Function in AN and BN 57
4.2 BOLD Response to Reward and Punishment Is Altered in AN 58
4.3 Implications 58
5 The Neurocircuitry of AN 59
6 Conclusions and Future Directions 60
References 61
Serotonin: Imaging Findings in Eating Disorders 69
1 Introduction 70
2 The Role of 5-HT Neurotransmitter Function in Eating Disorders 71
3 Brain Imaging Studies 73
3.1 5-HT2A Receptor 75
3.2 5-HT1A Receptor 77
3.3 Brain Regions/Pathways Enervated by 5HT1A/2A Receptors 79
3.4 5-HT Transporter 80
4 Conclusion 81
References 83
Dopamine-Based Reward Circuitry Responsivity, Genetics, and Overeating 90
1 Introduction: Dopamine Reward and Overeating 91
2 Relation of Dopamine Functioning to Overeating and Obesity 91
3 Genetic Variation in Dopaminergic Reward in Humans 93
3.1 The Taq1A Polymorphism of the DRD2 Gene 94
3.2 Variants in the DRD4 Gene 94
3.3 Variants in the Dopamine Transporter 95
3.4 Variants in the Catechol-O-Methyltransferase Gene 95
3.5 AKT 96
4 Appetite-Regulating Hormones and Peptides 97
5 Conclusion 97
References 98
Reward and Neurocomputational Processes 103
1 Introduction 104
2 Possible Mechanisms Underlying Reward System Abnormalities in AN 105
3 Taste and Reward System Activation Research in AN 106
4 Reward Pathway Function and Neurobiology 107
5 Reward Brain Imaging Studies and Anorexia Nervosa 108
6 Neurocomputational Modeling and Brain Imaging 109
6.1 Principals of the Temporal Difference Model 110
6.2 Temporal Difference Model Study Design 110
6.3 Data Analysis 111
7 Use of Neurocomputational Models and Testing of Alternate Models (Fig.2) 112
8 Preliminary Results 113
9 Limitations of the Model 114
10 Future Outlook 115
References 115
Cognitive-Behavioral Flexibility in Anorexia Nervosa 119
1 Introduction 120
1.1 Cognitive-Behavioral Inflexibility: A State or Trait Marker? 120
2 Temperament and Cognitive-Behavioral Flexibility 121
3 Neuropsychology 122
4 Neuroimaging 124
5 Neuromodulation 126
6 Conclusion and Future Directions 127
References 128
Neural Circuits, Neurotransmitters, and Behavior 132
1 Heterogeneous Expressions 133
2 General Behavioral Effects of 5-HT 133
3 Sources of Variation in 5-HT Activity 134
3.1 Nutritional Status 134
3.2 Genetic Factors Influencing 5-HT Activity: General Population 135
4 Serotonin and the EDs 135
5 Serotonin and Temperament in the EDs 136
5.1 Neurobiological Indices 136
5.2 Brain Imaging 137
5.3 Genetic Indices 137
5.3.1 5HTTLPR 137
5.3.2 Tryptophan Hydroxylase 138
5.3.3 5HT Receptors (5-HT2A and 5-HT2c) 138
5.4 Gene-Environment Interactions and Personality-Trait Expressions 139
6 Theoretical and Clinical Implications 139
7 Discussion and Conclusions 141
References 142
Part III: Genetics, Gender and Heritability 146
The Heritability of Eating Disorders: Methods and Current Findings 147
1 Overview 148
2 Genetic Epidemiology Methods: Family, Twin, and Adoption Studies 149
2.1 Family Studies 149
2.2 Twin Studies 150
2.3 Adoption Studies 152
3 Eating Disorder Endophenotypes and Component Phenotypes 152
3.1 DSM Criteria 153
3.2 Disordered Eating Behaviors 155
3.3 Eating Disorder Attitudes and Temperament 157
4 The Value of Family and Twin Studies in the Molecular Genetic Era 158
References 158
The Genetics of Eating Disorders 163
1 Background 164
1.1 The Genetic Architecture of Eating Disorders 164
2 Candidate Gene Studies 166
3 Linkage Analysis 168
4 Genome-Wide Association 169
4.1 Microsatellite-Based GWAS 170
5 Future Prospects 171
5.1 Array-Based GWAS 171
5.2 Copy Number Variants 171
5.3 Genome Sequencing 172
5.4 Gene-Environment Interaction 172
5.5 Epigenetics 173
Reference 175
The Influence of Gender and Puberty on the Heritability of Disordered Eating Symptoms 182
1 Introduction 183
2 Gender and the Heritability of Disordered Eating Symptoms 183
3 Puberty and the Heritability of Disordered Eating Symptoms 186
4 Conclusions 188
References 189
Part IV: Neuroendocrinologyand Animal Research 191
New Frontiers in Endocrinology of Eating Disorders 192
1 Introduction 193
2 Ghrelin and Obestatin 194
2.1 Ghrelin and Obestatin in Anorexia Nervosa 197
2.2 Ghrelin and Obestatin in Bulimia Nervosa 198
2.3 Ghrelin, Reward, and Cognition in Eating Disorders 199
3 Brain-Derived Neurotrophic Factor 200
3.1 BDNF in Anorexia and Bulimia Nervosa 201
4 Opioids 202
4.1 Opioids in Anorexia and Bulimia Nervosa 202
5 Endocannabinoids 202
5.1 Endocannabinoids in Anorexia and Bulimia Nervosa 203
6 Potential Therapeutics of Feeding Modulators 204
7 Conclusions and Perspectives 205
References 206
Animal Models of Eating Disorder Traits 212
1 Why Studying Eating Disorder Traits? 213
2 Eating Disorder Traits 214
3 Rational for Animal Models of Eating Disorders 216
4 How These Traits Are Mimicked in Animals 217
5 Future Directions 224
References 224
Neurobiology Driving Hyperactivity in Activity-Based Anorexia 231
1 Introduction 232
2 Animal Models for Anorexia Nervosa 232
2.1 The Activity-Based Anorexia Model 233
3 Leptin and Ghrelin Physiology 235
3.1 Leptin and Ghrelin in Patients with AN 237
4 Leptin and Ghrelin in Activity-Based Anorexia 238
4.1 Downstream Effector Mechanisms of Leptin and Ghrelin 240
4.1.1 Melanocortins and NPY 241
4.1.2 Opioids and Dopamine 242
5 Discussion 244
References 246
Part V: Translational Approach to Treatment 253
Translating Experimental Neuroscience into Treatment of Eating Disorders: Two Examples 254
1 Introduction 255
2 What Can We Learn from Schizophrenia Research? 256
3 Schemes for Studying Social Cognition and Socio-Emotional Processing 258
4 Social Cognition and Impact on Function 258
5 Socio-Emotional Processing in Anorexia Nervosa 259
6 Developing a Social-Cognitive Intervention for Anorexia Nervosa 261
7 Some Other Examples 262
8 Discussion 263
References 265
Cognitive Remediation Therapy for Eating Disorders: Development, Refinement and Future Directions 270
1 What Is CRT and How Can It Be Useful in Psychiatric Disorders? 271
2 Why Might CRT Be Useful in Eating Disorders? 272
3 Why Might CRT Be Useful for Adolescent Anorexia Nervosa? 274
4 What Is CRT in Detail for Adults? 276
5 Can CRT Modified for Use in Adolescents with AN? 277
6 How Can CRT Be Integrated into Focused Treatments for Eating Disorders? 279
6.1 The New Maudsley Model 279
6.2 Use of CRT on Short-Term Medical Unit for Adolescent AN 280
6.3 Fitting CRT to CBT in an Outpatient Setting for Older Adolescents and Adults with AN 282
7 What Are the Future Research Directions in Using CRT? 283
References 285
Incorporating Dispositional Traits into the Treatment of Anorexia Nervosa 289
1 Introduction 290
2 Developmental Considerations in Addressing Trait Features 291
3 The Role of Attention in Addressing Trait Features 293
4 Personality and Social Reinforcement Contingencies 294
4.1 Reputation Narratives 294
4.2 Niche-Building Processes 295
4.3 Role Modeling 296
4.4 Interim Summary 297
5 The Example of Perfectionism 297
6 Perfectionism Addressed Via Group Parent Training 300
6.1 Theoretical Model Guiding Intervention Content 300
6.2 Attention Focus in Group Parent Training 302
6.3 Shaping as Attention Retraining to Goal Approximations 304
6.4 Role Modeling 306
6.5 Social Reinforcement Contingencies 307
6.6 Niche Environments 308
6.7 Changes in Perfectionism in Adolescent Anorexia Nervosa 309
7 Summary 310
References 310
Index 315