Brain imaging studies in mood and anxiety disorders: special emphasis on the amygdala

Human studies attempting to elucidate brain functioning in health and disease are crucial for our understanding of neuropsychiatric disorders. In the past, scientists relied heavily on neurological lesion studies to understand the functional roles of brain areas. In the last few decades, brain imaging research has made it possible to investigate the molecular and synaptic neuronal events as well as the functioning of neuronal networks in vivo, in patients with neuropsychiatric illnesses. In this context, the functional role of the amygdala has been a focus of neuroimaging studies by leading researchers. Several of these researchers presented papers at a conference, entitled The Amygdala in Brain Function: Basic and Clinical Approaches, that provided the basis for this volume. These papers follow this review in the current volume. The present paper briefly summarizes the highlights of the different presentations, focusing on the functional diversity of the amygdala and its role in different neuropsychiatric disorders; reviews the various brain imaging technologies currently available; and discusses the major findings on the pathophysiology and treatment of depression, bipolar disorder, and anxiety disorders.