Teen Stress Linked to Higher Postpartum Depression Risk

Introduction

A Johns Hopkins Medicine-led research team has unveiled significant findings linking social stress during adolescence in female mice to prolonged elevation of the hormone cortisol after childbirth. This study, published online on April 11, 2024, in Nature Mental Health, aligns these hormonal changes with those seen in postpartum women exposed to adverse early life experiences, suggesting that early life stress might exacerbate postpartum depression (PPD).

The Study’s Implications for Postpartum Depression

The study indicates that current drug treatments for PPD may sometimes be less effective at addressing relevant chemical imbalances in the brain. Thus, alternative treatment methods could be more beneficial. Previous studies suggest that about one-third of psychiatric conditions do not respond to current therapies, and PPD is notably challenging to treat, according to Akira Sawa, M.D., Ph.D., the senior author of the study and director of the Johns Hopkins Schizophrenia Center. Sawa highlights the need for more individualized diagnosis and treatment for PPD, advocating for a precision medicine approach.

Understanding Postpartum Depression

The federal government’s Office on Women’s Health estimates that PPD affects 7% to 20% of women, typically within six weeks after childbirth. Symptoms include feelings of sadness, anxiety, and fatigue, which can interfere with basic self-care and infant care.

The primary treatment for PPD involves selective serotonin reuptake inhibitors (SSRIs), which enhance the effects of serotonin, a natural brain chemical that helps regulate mood. However, SSRIs are only effective for about half of the patients. Some severe cases are treated with IV infusions of drugs targeting GABAA, a brain chemical associated with nerve hyperactivity, but these treatments are costly and generally reserved for the most resistant cases of PPD.

The Study’s Methodology and Findings

The Johns Hopkins-led team aimed to expand on the evidence that adverse life events might affect the likelihood and severity of PPD. Previous research indicated that PPD is more prevalent among teenagers and urban populations.

In the study, the researchers worked with mice, creating four test groups: unstressed virgins, stressed virgins, unstressed mothers, and stressed mothers. The stressed mice were subjected to social isolation during adolescence. At seven days postpartum, the stressed mothers exhibited decreased mobility and sugar preference, both markers of depression, persisting for at least three weeks after delivery.

The critical phase of the study involved testing plasma levels of several hormones. The researchers found elevated cortisol levels in both stressed and unstressed mothers, but unstressed mothers’ cortisol levels returned to normal postpartum, whereas stressed mothers’ levels remained high for one to three weeks. This prolonged elevation of cortisol was correlated with behavioral changes in postpartum mice that had experienced social isolation during adolescence.

Translating Findings to Human Treatment

If these findings apply to humans, it suggests that glucocorticoid receptor (GR) antagonists, which block the effects of elevated cortisol, could be a novel treatment option for PPD. Mifepristone is one such drug. Sawa emphasizes that the alternative treatment suggested by the mouse study could enable mothers to be treated at home, avoiding separation from their babies, and target a different depression mechanism specific to PPD.

The team plans to collect precise data on cortisol levels in people with PPD to determine if GR antagonists would be more effective than current treatments and to conduct clinical trials with alternatives to SSRIs.

Collaborators and Future Directions

The research team includes Sedona Lockhart, Jennifer Payne, Gary Wand, Daniel Wood, and Kun Yang from Johns Hopkins Medicine, along with Minae Niwa, Adeel Ahmed, Shin-ichi Kano, Kyohei Kin, and Jose Francis-Oliveira from the University of Alabama at Birmingham Heersink School of Medicine.

This study provides crucial insights into the underlying mechanisms of PPD and highlights the need for more targeted and individualized treatment approaches, potentially transforming how PPD is managed and improving outcomes for affected mothers and their babies.

Source: Materials provided by Ohio State University. Original written by Emily Caldwell. Content edited for style & length.