Dealing with differential gender and age effects in evoked potential studies of psychopathology.

Data selected from comprehensive EP studies of a large sample of psychiatric patients and nonpatients illustrate the point that matching patient and control populations for age and gender is essential, but not sufficient, to control for these subject variables. It is necessary to test for the interactions resulting from different relationships between EP measures and gender and/or age in different diagnostic groups and to examine differences between subgroups defined by gender and age.