Letters Section Editor: Robert M. Golub, MD, Senior Editor.
In Reply: Dr Michels refers to our discussion of limitations inherent to the demonstration of causality in observational studies, which might be fully addressed if depressed mothers were randomly assigned to a treatment that clearly produced remission vs one that clearly did not.1 However, ethical considerations would obviously preclude this approach. He suggests an alternative mechanism—a prior genetic or environmental common cause that predicts symptom severity in both the mothers and their children—that may account for the association between maternal remission and child improvement. Such a mechanism, however, is not consistent with our data since the severity of maternal depression, as measured by the Hamilton Rating Scale for Depression, was not associated with either the prevalence of child disorders at baseline (prior to the mother's treatment) or with changes in rates of children's disorders at the 3-month follow-up assessment.
Weissman MM, Alpert JE, Fava M, Trivedi MH, Rush AJ. Remission of Maternal Depression and Children’s Psychopathology—Reply. JAMA. 2006;296(10):1232-1234. doi:10.1001/jama.296.10.1233-b