Any effort to explain these seemingly discrepant findings only raises more questions. First, how is a "change of personality" measured? Could the discrepancy in findings between these two studies (2, 3) be explained just by the use of different measurement tools? Second, is everyone equally affected by antidepressant treatment? According to Dr. Knutson and colleagues (3), volunteers were not equally affected. Does this mean that some may be affected and some may not be affected at all? Could this help define the biological substrate of personality? Third, would a design with the use of an active placebo help resolve the discrepancy between the two studies? Fourth, could it be that serotonergic antidepressants just help "normal" and other people tolerate stress better, as suggested by Norden (4)? Fifth, are these personality changes permanent? Neither of the two studies addresses the last issue, even though it could be easily done by repeating personality measures 1, 3, and any number of months after discontinuing the antidepressant. Maybe the authors could provide us with these data.