Maternal mental illness is the leading cause of pregnancy-related deaths in the US, according to a new evidence review, but national initiatives developed to combat the issue often fail to prioritize mental health.

The maternal mortality rate in the US is two- to threefold greater than in other high-income countries, and it has only increased in recent years, according to the review, which was published Wednesday in the journal JAMA Psychiatry. More than 80% of pregnancy-related deaths in the US are preventable, the US Centers for Disease Control and Prevention says.

The new review examined 30 recent studies and 15 historical references to highlight the underrecognized contribution of mental illness to maternal mortality.

The researchers determined that mental health disorders such as suicide and opioid overdose are responsible for nearly 1 in 4 maternal deaths in the US. That’s almost double the rate of maternal death from postpartum hemorrhage, the second leading cause of pregnancy-related death, according to the reports from three dozen maternal morbidity and mortality review committees, state-based organizations that review maternal deaths.

“The contribution of mental health conditions to the maternal morbidity and mortality crisis that we have in America is not widely recognized,” Dr. Katherine Wisner, associate chief of perinatal mental health at Children’s National Hospital and co-author of the evidence review, said in a news release. “We need to bring this to the attention of the public and policymakers to demand action to address the mental health crisis that is contributing to the demise of mothers in America.”

The researchers emphasized that women are at higher risk for new psychiatric disorders during and immediately after pregnancy. About 14.5% of pregnant people have a new episode of depression during pregnancy, while another 14.5% develop an episode during the first three months after birth, according to a report for the Agency for Healthcare Research and Quality, cited by the review.

However, only 20% of women are screened for postpartum depression, Wisner said.

“Given that this is a time that many mothers have contact with healthcare professionals, it’s critically important that all mothers are screened and offered treatment,” she said. “Mental health is fundamental to health – of the mother, the child and the entire family.”

Access to comprehensive maternity care is limited in many states. More than 400 maternity services nationwide closed between 2006 and 2020, leaving nearly 6 million people in “maternity care deserts” with no or limited access to maternity care, according to a study published in January 2023.

This lack of accessible maternity care creates stress for mothers who must travel long distances and increases the risk that health complications go untreated, according to the evidence review.

Limitations to reproductive health care, including access to abortion, also affect maternal mental health. A study highlighted in the review found that enforcement of targeted regulation of abortion providers (TRAP) laws, which lead to fewer abortion providers, was associated with a 6% higher annual rate of suicide in reproductive-age people.

The review also emphasized the negative health consequences of maternal trauma and prenatal stress and underscored the role of social determinants of health such as economic stability, education, and environment in pregnancy outcomes.

Members of racial and ethnic minority groups are more likely to enter the perinatal period with stressors due to systemic inequities, according to the review. This is evident in the stark racial disparities in maternal death: The mortality rate for Black mothers was 2.6 times higher than for white mothers in 2021, according to the CDC’s National Center for Health Statistics.

Black mothers are twice as likely to experience maternal mental health conditions but half as likely to receive treatment compared to White mothers, Dr. Jessica Pineda, assistant professor of psychiatry and director of the Women’s Mental Health fellowship at Brown University, said in an email to CNN.

“Racial disparities that contribute to lack of treatment for mental health disorders likely also include barriers related to transportation, childcare and cost,” she said. “As well as distrust of the health care system.”

National initiatives like the White House Blueprint for Addressing the Maternal Health Crisis have mobilized funds and resources to address the maternal mortality crisis in the US, but they need to prioritize mental health more, according to the review.

“We cannot transform mental health solely through the health care system. We must also address the determinants of behavioral health, invest in community services, and foster a culture and environment that promotes mental wellness and recovery,” the White House said in a statement in March 2022 addressing the national mental health crisis.

The researchers recommend improving interdisciplinary training in obstetrics and mental health for health professionals, mandating universal maternal mental health screening and promoting public education about family planning options.

The review also highlights programs that have been developed to prevent postpartum depression, such as the US Preventative Health Services Task Force Rose Program and the Mothers and Babies program, and successful models to support access to perinatal mental health care, such as the Massachusetts Child Psychiatry Access Program for Moms, which is funded by the Massachusetts Department of Mental Health.