Depression, weight gain, and low birth weight adolescent delivery: do somatic symptoms strengthen or weaken the relationship?

Objective: To determine if omission of the Center for Epidemiologic Studies Depression Scale (CES-D) items that assess the somatic symptoms of depression improves the psychometric properties of the scale and utility of the CES-D diagnosis of depression for predicting four adverse obstetrical outcomes that have been tentatively linked to maternal depression.

Methods: A cohort of 1684 13-21-year-old participants in an adolescent-oriented maternity program completed the CES-D at enrollment. Chi-square analyses were used to compare the predictive capacity of depression diagnosed by the full CES-D and the 14-item non-somatic subscale of the CES-D. The reliability and construct validity of the two scales were also compared.

Results: Removing the somatic component of the CES-D decreased the proportion of adolescents who met screening criteria for depression. However, it did not improve the psychometric properties of the scale. The reliability (Cronbach alpha: 0.87) and construct validity (depressed adolescents were significantly more psychologically stressed and had poorer social support) of the two scales were equivalent. Regardless of the scale used, adolescent mothers who were depressed in the second and third trimesters were at increased risk for inadequate weight gain and both small for gestational age fetuses and preterm delivery (ORs 1.6-1.8). The differences in case definition and predictive capacity were most evident when the CES-D was administered during the first trimester. However, overall effect sizes were nearly identical with the two scales.

Conclusion: Removing the somatic component does not improve the psychometric properties of the CES-D or the predictive capacity of the CES-D diagnosis of depression for three sentinel obstetrical outcomes. This information should be reassuring to researchers and clinicians as most studies of the causes and consequences of maternal depression during and after pregnancy use the full CES-D scale.