A new study points to the important role fathers play in their children's emotional and behavioral health. The study shows that a father in good mental health can substantially reduce the negative influence of a mother's poor mental health on a child's behavioral and emotional well-being. ''If a mother and father are depressed, the odds that a child will have behavioral or emotional problems go up eight-fold,'' according to Robert S. Kahn, M.D., M.P.H., a physician/researcher in the Division of General and Community Pediatrics at Cincinnati Children's and the study's lead author. ''The risk is less elevated if only the mother reported poorer mental health and not elevated at all if only the father reported poorer mental health.''