Compiled from presentations given at the 2004 American Psychopathological Association (APPA) annual meeting, Medical and Psychiatric Comorbidity Over the Course of Life reviews the comorbidity of mental and chronic physical syndromes in an epidemiological and life course context, offering fresh insights and identifying crucial clues to the etiology and nosological distinctiveness of both physical and mental disorders. Once relatively ignored, the study of lifetime comorbidity has the potential to suggest etiological clues and to advance both our understanding of primary diseases and our ability to prevent secondary disorders. The concept of the etiologically relevant period, which begins with the earliest causal action and ends with diagnosis, is vital to the study of comorbidity. In sections focusing on epidemiology, risk factors, mood disorders, emotions and health, and schizophrenia, Medical and Psychiatric Comorbidity Over the Course of Life discusses the critical aspects of the life course characteristics of the etiologically relevant period, including duration and gene action; fetal growth and puberty; point of irreversibility; allostatic burden; and multiple causes throughout the life course. Medical and Psychiatric Comorbidity Over the Course of Life will prove invaluable for practitioners in general and consultation-liaison psychiatry, family practice and internal medicine, and psychosomatics, behavioral medicine, and health psychology.