This article explores the rationale for early detection and intervention in schizophrenia. The most compelling reason is the disorder's severity and chronicity and our knowledge that, while many treatments for schizophrenia are effective, they are also limited and palliative. This state of affairs suggests that researchers pay closer attention to schizophrenia's premorbid and onset phases, when the vulnerability to psychosis becomes expressed and the neurobiological deficit processes driving symptom formation appear to be the most active. We review the evidence that brain plasticity can be retained or reversed despite deficit processes. This evidence includes the putative attenuation of the severity of schizophrenia throughout the 20th century, retrospective and prospective linkage of earlier neuroleptic treatment and better long-term outcome, and data from a program designed to intervene in the prodromal phase of disorder. While the evidence to date does not demonstrate that early intervention with known treatments can change the natural history of schizophrenia, it is suggestive enough (for both biological and psychosocial treatment) to support further investigation. Focusing on the early course of schizophrenia also offers the possibility of identifying potential patients long before onset using vulnerability markers and of making more feasible primary prevention efforts. Finally, studies of untreated psychosis in first-episode cases have revealed that patients are often actively psychotic for a very long time before they get help. Bringing treatment more rapidly to a person who has been psychotic is in itself enough to justify early detection efforts.