Schizophrenia is the most prevalent of the major psychoses, but the underlying neurobiology of this debilitating disorder remains mysterious. Recent developments in molecular biology, neuroanatomic pathology, neurochemistry, and functional imaging suggest that a number of factors converge to produce schizophrenia. Specifically, an early neurodevelopmental "lesion," possibly within the mesial temporal lobe, may contribute to later temporolimbic-prefrontal dysfunction as the nervous system matures. Genetic factors appear to facilitate liability to schizophrenia, and dopaminergic and possibly other neurotransmitter systems may mediate clinical expression of the illness through newly recognized receptor subtypes.