Identifying Trajectory Classes of Postpartum Depressive Symptoms

Women in their first year postpartum can be categorized into 2 trajectory classes of postpartum depressive symptoms, according to research results published in the Journal of Affective Disorders. Furthermore, women who have persistently high depressive scores are considered high risk and are associated with a distinct set of risk factors.

To assess the trajectory of depressive symptoms in women during their first year postpartum and identify risk factors associated with various trajectory classes, researchers collected data on the depressive symptoms of 1374 Norwegian women (average age at birth: 30.4 years) at 1.5, 4, 6, and 12 months postpartum.

Overall, depressive symptoms decreased initially (P <.01), then flattened out at 6 months (P <.01). Via mixture analyses, the researchers identified 2 classes of women with distinct trajectories: low-risk (n=1249; 91%), who generally scored low on depressive symptoms; and high-risk (n=119; 9%), who had elevated depression scores just below the cut-off for minor depression. The high-risk group was associated with risk factors such as complications after birth, elevated depressive symptoms during pregnancy, and previous mental illness.

In addition to these primary outcomes, the researchers also examined the association between trajectory classes and supportive counseling. Overall, they found that most women did not receive supportive counseling, but the odds ratio (19.78) was higher in high-risk women than in low-risk women — while 140 low-risk women received counseling, only 69 high-risk women received counseling.

Several limitations to this study were reported. The most notable was that women included in the sample had a higher education level than the general population and generally low depressive symptom scores, which might have hindered the study’s ability to identify classes with severe symptoms.

Based on their findings, the researchers said, “clinicians need to be aware of the heterogeneity among postpartum women, risk factors associated with these high-risk women, and include assessments of trajectories for the early prevention of postpartum depression.”

Reference

Drozd F, Haga SM, Valla L, Slinning K. Latent trajectory classes of postpartum depressive symptoms: a regional population-based longitudinal study [published online August 1, 2018]. Journal of Affective Disorders. doi:10.1016/j.jad.2018.07.081