Schizophrenia remains a poorly understood and yet a profoundly serious condition among all the major medical illnesses. We have witnessed a major shift in the past 5 years with the belief now that diagnosing and intervening early may have a positive influence on the outcome of schizophrenia. This shift has led to a search for key diagnostic clusters to enhance early diagnosis as well as to concerted efforts to find biomarkers of disease and disease progression. To that end, this issue of the Psychiatric Clinics of North America is dedicated to these contemporary issues that promote “early intervention” in schizophrenia. Distinguished academic clinicians and neuroscientists provide comprehensive overviews of the present state of knowledge on the epidemiology, early clinical characteristics and diagnostic changes, proposed pathogenesis, neurobiology, and treatment requirements for this disorder.