These are exciting yet frustrating times for psychiatry. Our knowledge of basic brain function continues to increase at an accelerating pace as the tools of biology—from genetics and epigenetics to detailed exploration of brain circuits in animals and humans—become ever more powerful and penetrating. Yet this explosion of knowledge of the brain has not been translated into fundamental advances in our understanding of the pathophysiology of most major psychiatric syndromes, the diagnosis of these syndromes based on their underlying biological mechanisms, or the treatment and prevention of mental illness.
Why has there been such a divide between our basic knowledge and clinical advances? First and foremost, the brain has proved to be far more complicated than ever imagined a generation ago, and the disorders of the brain that manifest primarily in behavioral abnormalities (i.e., mental illness) are far more complicated too in terms of their genetic causes and the associated abnormalities at the epigenetic, cellular, and circuit levels. We have also learned that effective translation will not occur automatically or organically and will require a far more concerted effort than mounted thus far to link findings in basic neurobiology and genetics to the human syndromes. The good news is that leaders at the National Institutes of Health, academia, and industry recognize the need for such collaborations, with many exciting ventures now underway or planned to meet the challenges ahead.
We have completely revamped the fourth edition of Neurobiology of Mental Illness to address these challenging yet promising times. We have recruited two new book editors to add depth and breadth of expertise, and have engaged a team of all new section editors, each of whom represents a leader in his or her fields. Accordingly, new authors have been enlisted for a majority of the chapters that now comprise this book, with many new chapters added and old ones removed to reflect progress in the field. The result is a thoroughly updated view of the state of psychiatry, both its basic underpinnings and clinical evidence, with a view toward advances that can be expected in the coming years and the methodology that will bring us there.
As before, Section I provides an overview of basic neuroscience that is relevant to clinical psychiatry and expanding its foundations. Molecular neurobiology and molecular genetics are emphasized in the context of brain development, neuropharmacology, neuronal function, and neural networks and plasticity, with an eye on their contribution to complex behaviors.
Section II reviews the methods used to examine the biological basis of mental illness in animal models and in humans. This part has been expanded to reflect critically important technical advances in complex genetics (including powerful sequencing technologies and related bioinformatics), epigenetics, stem cell biology, optogenetics, cognitive neuroscience, and brain imaging. We believe that this range of exciting methodologies offer unique opportunities for the translation of preclinical and clinical research into badly needed breakthroughs in our therapeutic toolkit.
The remaining parts of the book cover the neurobiology and genetics of major psychiatric disorders: psychoses (including bipolar disorder), mood disorders, anxiety disorders, substance abuse disorders, dementias, disorders of childhood onset, and special topic areas. Each of these parts has been augmented in several different areas as a reflection of research progress. The last section, on special topics, includes chapters that address diagnostic schemes for mental illness. The release of our new edition coincides with the publication of DSM-5 (Diagnostic and Statistical Manual-5) by the American Psychiatric Association. Unfortunately, the diagnostic classification system utilized by DSM-5 remains limited by necessity, because it is still based primarily on phenomenology rather than etiology and pathophysiology. Alternative perspectives on diagnosis, for example, RDoC (research domain criteria), are therefore also presented. We predict that the research advances reviewed in our textbook will ultimately lead to diagnostic systems in which genetic and neurobiological abnormalities have a primary role.
This edition of Neurobiology of Mental Illness reflects the continuing reintegration of psychiatry into the mainstream of biomedical science. The research tools that are transforming other branches of medicine—epidemiology, genetics, epigenetics, molecular and cell biology, imaging, and medicinal chemistry—will also one day transform psychiatry. It is our hope that, like us, the reader is optimistic that the progress in genetics and in molecular, cellular, and systems neuroscience described in this textbook will eventually break new ground in the diagnosis, treatment, and prevention of disabling psychiatric disorders.
The Editors