My ideas for this book have been evolving over the last several years as I have been working in the animal modeling area and have seen it change rather dramatically. There have been tremendous advances, both in methodology and in conceptualization, yet the literature is scattered in journals encompassing many disciplines. In particular, there have been only very limited attempts to write about the philosophical, conceptual, and controversial issues in this field; to pull together diverse findings; and to provide some general perspective on its future. As will probably be apparent, I am a clinical psychiatrist who also has a fundamental interest in animal behavior, especially primate social behavior. I entered the field from a clinical research standpoint to devel op some animal models of depression after being stimulated to do so by Dr. William Bunney, then at the National Institute of Mental Health and now at the University of California-Irvine. The field has grown rapidly since then and there is considerable research activity. Indeed, the re search activity has grown more rapidly than our conceptualization of what animal models are and are not. Animal preparations are now available for studying specific aspects of certain types of psychopathology. Thoughtful workers in the animal modeling field no longer talk about comprehensive models but rather about more limited experimental preparations in animals for studying certain specific aspects of human psychopathology."

In this book we present a conceptually integrated approach to disorders of mood. These disorders are defined narrowly as the clinical syndromes of mania and melancholia. The latter is our particular focus, for the simple reason that it is more common and thus more is known about it. Our approach owes much to Adolf Meyer, who first used the term psychobiology. It was he who emphasized in a practical way the importance of the clinician consider ing the joint contribution of psychosocial and biological factors in the genesis of mental disorders. However, until the 1960s, our relative ignorance of basic mechanisms that link brain and behavior prevented the development of a genuine psychobiological perspective. Thus Meyer's work was concerned largely with teaching the importance of the personal biography and a consideration of social history in the development of mental disorder. We feel that sufficiently rigorous data have now emerged in psychia try to permit tentative but real psychobiological integration. Affective illness is proba bly the most promising area for an attempt at such a synthesis. It is our belief that the theory and clinical practice of psychiatry now can be woven into a coherent theme, integrating insights and evidence generated by the psychodynamic, biological, and behavioral methods; hence in part we review the emerging psychobiology of mood disorders with the hope that it can serve as a generic paradigm for other psychiatric syndromes."