Prenatal Depression May Affect Fetal Brain Development, Research Shows

Depression during pregnancy could change a developing fetus' brain and increase the risk of depression later in life, according to a new study published in August in the Journal of Neuroscience.

They found that fetuses of women with greater prenatal depression symptoms had weaker white matter connections between brain regions involved in emotional processing. These conclusions may explain why children of depressed mothers have a higher risk of developing depression themselves, researchers concluded.

Neural Connections

Researchers conducting the study looked at 54 pregnant women and asked them to answer Edinburgh Postnatal Depression Scale (EPDS) survey questions pertaining to their depression symptoms during their second and third trimester, and also at three months postpartum. They also employed diffusion MRI, an imaging technique that highlights structural connections between brain regions.

An analysis of these MRI results showed that white matter connections were weakened in the brains of pregnant individuals who were experiencing prenatal depression.

The next step was to observe the children themselves, which came in the form of dMRI scans taken between the ages of 4 and 5. They then performed behavioral assessments within six months of these brain scans. Researchers found that children whose mothers experienced depression during pregnancy were more likely to exhibit erratic behavior and mood instability. This result was directly linked to weaker white matter connectivity in the amygdala-frontal pathway.

White matter is a vast neural system that joins all four lobes of the brain as well as the limbic system, considered the "emotion center" of the brain. Without strong white matter connections, the different parts of the brain have difficulty communicating with each other.

For example, a 2018 meta-analysis of prenatal depression studies that looked at children's development up to age 18 concluded that in addition to depression, children may also be at higher risk for anxiety and behavioral problems.

Prenatal Depression is a Common Problem

It's estimated that up to 1 in 5 women have some type of pregnancy-related mood or anxiety disorder, and this can be due to a number of risk factors according to Kecia Gaither, MD, MPH, FACOG, director of perinatal services at Lincoln Hospital in the Bronx, New York. Those include:

• History of depression or mood disorder
• Lack of familial or social support
• Issues with significant other
• Financial issues
• Substance abuse disorders
• Family or domestic violence
• Chronic stress or illness
• Anxious or negative feelings about the pregnancy
• Pregnancy occurring at a young age

Physicians address depression with screening questions, appraisals by family members, behavioral monitoring during prenatal visits, and discussions with patients, says Gaither. Any findings that raise an alarm are referred for further evaluation with a psychiatrist, often along with assessment for an underlying medical cause for the issue, such as thyroid dysfunction.

Potential Depression Symptoms

Going through pregnancy is rife with physical and emotional changes, and sometimes it can be difficult to spot depression. Some women may chalk it up to being part of the transition, especially because pregnancy symptoms like fatigue or irritability overlap with depression signs.

"This is a common problem with pregnant women that needs to be recognized by patients, their families, and their doctors, and it's crucial to know symptoms so screening can be done," says Gaither.

Also, there's a prevailing belief that depression is always associated with sadness or feeling despondent, but those aren't always present, according to Scott Dehorty, LCSW-C, a social worker with Delphi Behavioral Health Group. In fact, he notes, signs like those are often seen less than other symptoms such as anxiety and fatigue.

"Feeling down isn't really all that common for someone with depression as much as other symptoms," Dehorty says. Those can include:

• Absence of joy or pleasure
• Disinterest in activities that you used to enjoy
• High levels of anxiety, especially in those with chronic illness
• Sudden mood shifts
• Increased pain unrelated to normal pregnancy effects like tight muscles
• Difficulty falling asleep or staying asleep, paired with daytime fatigue
• Lack of motivation
• Lower levels of self-care, including personal hygiene
• Disinterest in social connections

Fortunately, treatment is available, but is highly individualized, says Gaither, which is why it's important to have a conversation with your doctor about what's going on. Just because you're pregnant doesn't mean you can't take antidepressants, but there are a couple options—such as lithium and valproate—which are not recommended during pregnancy, Gaither advises.