To the Editor: I thank Drs. Read and Bentall for their interest in my editorial comments about brain development and the causes of schizophrenia. I am pleased they are in agreement with the overall argument made. They rightly point out that risk factors across the entire range of prenatal and postnatal development ultimately contribute to schizophrenia and call our attention to the literature regarding early childhood adversity. As they note, hypothalamic-pituitary-adrenal axis alterations and epigenetic regulation are likely candidate mechanisms that deserve study. Their discussion of the potential role of environmental enrichment is very important, since we realize that it may be difficult to prevent many of the multiple causes of schizophrenia but may be possible to identify and modify developmental trajectories of risk.