In recent years increasing evidence is pointing toward white matter abnormalities in schizophrenia and other psychiatric disorders. The present paper will provide an overview over the role of myelin in cognition and brain function, and its potential involvement in brain disorders. Furthermore, we will examine one particular experimental model for the study of dysmyelination, created by the administration of the toxin cuprizone. Cuprizone, a copper chelator, causes white matter abnormalities in rodents. The administration of cuprizone during specific developmental periods allows for the targeting of specific brain areas for dysmyelination. Thus, cuprizone can be used to study the pathogenesis and pathophysiology of myelin deficiencies in the central nervous system, and its effect on behaviors relevant to psychiatric disorders.