Chantal Henry ^1,2,3,4, Mary Phillips^5,6,7, Ellen Leibenluft⁸, Katia M'Bailara^9,10, Josselin Houenou^1,2, Marion Leboyer^1,2,3,4

1INSERM, U955, IMRB, departement de Genetique, Creteil, F-94000, France, ²Universite Paris-Est, Faculte de Medecine, IFR10, Creteil, F-94000, France, ³AP-HP, Hopital Henri Mondor-Albert Chenevier, Pole de Psychiatrie, Creteil, F-94000, France, ⁴Fondation FondaMental, Fondation de cooperation scientifique, France, ⁵Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA, ⁶Department of Psychological Medicine, Cardiff University School of Medicine, Cardiff, UK, ⁷Institute of Psychiatry, King's College London, UK, ⁸Emotion and Development Branch, Intramural Research Program, National Institute of Mental Health, Department of Health and Human Services, Bethesda, MD, USA, ⁹Laboratoire de psychologie, Universite Victor Segalen, Bordeaux 2, France, ¹⁰Departement de Psychiatrie Adulte, CHS Charles Perrens, Bordeaux, France

TABLE OF CONTENTS

1. Abstract

2. Introduction

3. Clinical data regarding emotional reactivity in bipolar and major depressive disorders

3.1. Emotional reactivity in euthymic bipolar patients

3.1.1. Self-report studies

3.1.2. Experimental studies

3.2. Emotional reactivity during manic and mixed episodes

3.2.1. Self-report studies

3.2.2. Experimental studies

3.3. Evaluation of emotional reactivity during depression

3.3.1. Identification of two subtypes of bipolar depression: Self-report studies

3.3.2. Emotional reactivity in major depressive disorder: Self report and experimental studies

4. Summary of clinical data on emotional reactivity during mood disorders

5. Brain imaging and abnormal emotional reactivity in mood disorders

6. Neurochemical systems, genes and emotional reactivity

7. Conclusion

8. References

1. ABSTRACT

Background assessment of emotional reactivity, defined as rapid emotional responses to salient environmental events, has been neglected in mood disorders. This article reviews data showing the relevance of using emotional reactivity to better characterize bipolar mood episodes. Method We reviewed clinical data on emotional reactivity during all phases of bipolar disorders (euthymic, manic, mixed and depressive states) and brain-imaging, neurochemical, genetic studies related to emotional reactivity disturbances. Result Euthymic bipolar patients show mild abnormalities (hypersensitivity to emotional stimuli and higher arousability) in comparison to controls. Both manic and mixed states are characterized by a significant increase in emotional reactivity. Furthermore, emotional reactivity may discriminate between two types of bipolar depression, the first being characterized by emotional hypo-reactivity and global behavioral inhibition, the second by emotional hyper-reactivity. Brain-imaging studies can help to identify the underlying mechanisms involved in disturbances of emotional reactivity. Conclusion Emotional reactivity can be used to refine more homogeneous pathophysiological subtypes of mood episodes. Future research should explore possible correlations between biomarkers, response to treatments and these clinical phenotypes.