Zigun et al have raised sev- eral issues concerning our article. Their major concerns appear to be the following: (1) the control group may be atypical; and (2) they take exception to a statement attributed to us that "given the phenomenological differences in the manifestations of schizophrenia between men and women, the reported gender differences in ventricular enlargement may be due to different types of illness or different etiologic factors."
Zigun et al do not accurately summarize the contents or conclusions of our article, since many of the issues raised in their letter were already discussed in the article, while the phenomenology of schizophrenia in relation to gender differences was not discussed at all.
An Atypical Control Group-—
To our knowledge, this study reports on one of the largest samples of carefully screened healthy normal volunteers that has been studied with computed tomography (CT). The total sample size of the