Growing up with stress is not healthy for infants and young children, says Delia M. Vazquez, M.D., an associate professor of pediatrics and psychiatry in the U-M Medical School. Children who live with chronic stress are more likely to develop depression early in life. In extreme cases, children even stop growing until their high-stress environment is changed.

To learn more about the relationship between a mother’s depression and development of the stress hormone system in her infant, Vazquez is involved in a long term study of new mothers at U-M Women’s Hospital who have a high risk of developing depression.

By measuring a stress hormone called cortisol in saliva, researchers can track the relationship between a mother’s mood, the personal interaction with her infant and the normal development of cortisol levels in her child.

“Cortisol follows a day-and-night cycle; it is high in the morning and low at night,” Vazquez explains. “Cortisol production in depressed patients is high when it should be low. In contrast, children living in adverse environments, such as third world orphanages, have low cortisol levels when these should be high. We wonder if a child’s cortisol levels would be a mirror image of their caretaker. Is there a set point that is in part genetic and in part from their early life experience, beginning during the first year of life? Can we intervene early to stop a negative outcome, such as depression? How early? These are the types of questions we hope to answer.”