Tassy Hayden

Diabetes, Depression, and Therapy in Expectant Mothers: Impact on Infant Development. Tassy Hayden¹, Tamara Hershey², Biology Department, Washington University, Saint Louis, MO¹; Psychiatry Department, Washington University Medical School, Saint Louis, MO.²

Millions of Americans experience a depressive illness each year, with millions more being affected by diabetes. Depression is highly comorbid with diabetes and has been linked to poorer blood glucose control and greater diabetic complications. Alone, diabetes or depression during pregnancy has negative implications for the health and neural development of fetuses, increasing the risk of poor infant cognitive and motor outcomes. As both of these illnesses reach almost epidemic proportions, the possible impact and treatment of their joint occurrence during pregnancy become areas of great research interest.

A study was conducted (P. Lustman, PI) to examine the effects of poor glucose control (secondary to diabetes) and depressive symptoms during pregnancy on measures of infant outcome. Diabetic, pregnant women were recruited from high-risk clinics at three Saint Louis hospitals and classified as depressed or not depressed. Half of the depressed population was randomly assigned to ten weeks of cognitive-behavioral therapy (CBT), the other half to ten weeks of supportive counseling (SC; a non-directive, empathetic therapy). All women’s HbA1c levels, indicative of long-term blood glucose control, as well as scores on depression indices, were collected for the remainder of their pregnancy. The children of these women were examined at six weeks, six months, and one year using tests of cognitive, motor, and temperament development.

Analyses revealed that HbA1c levels were not significantly associated with infant outcome, and treatment of depression did not lead to improvement of A1c levels. However, the glucose control exhibited by this sample was much better than expected, with less than a quarter of women attaining HbA1c readings indicative of chronic hyperglycemia.

In addition, infants of mothers who exhibited depressive symptoms during pregnancy scored less optimally on several measures of behavior. However, socio-economic status (SES) confounded the depression classification in this sample. When SES was entered as a covariate in these analyses, some of the effects of depression disappeared, suggesting that future studies of this nature should carefully consider SES. No evidence of additive effects of diabetes and depression was found on infant outcome. A larger sample size is recommended because of the complicated course of these disorders; perhaps yielding data more sensitive to detecting additive effects.

Finally, findings regarding depression treatment were more straightforward. CBT improved mother’s depression scores, although SC did not. Overall, the infants of women in the CBT group performed as well as infants of non-depressed mothers, and both groups performed better than infants of mothers in the SC group. Further, percent improvement in depression score during pregnancy was correlated with better infant outcome, including higher scores on the Mental and Motor Development Indices (MDI and PDI) of the Bayley Scales and on an independent observer’s ratings of infant behavior. These results indicate that CBT may be valuable as a treatment for depression in pregnant diabetic mothers and additionally helps to offset the negative effects of depression during pregnancy on infant cognitive and motor outcome.