A child whose parents were diagnosed with depression at some point after the child’s birth is more likely to perform poorly in school at age 16, according to a new study out of the Drexel University School of Public Health. The study examines the link between parental depression and child development, and highlights the importance of screening pregnant and postpartum women (and men) for depression.

The researchers examined over 1.1 million children in Sweden who were born between 1984 and 1994. They tracked their inpatient and outpatient records, as well as school grades, and analyzed whether their mothers or fathers had depression before the child’s birth or any time before the child’s final year of school. Some 3 percent of mothers and 2 percent of fathers were diagnosed with depression before their kids got to their final school year.

They found that children fared worse in school if their parents had been diagnosed with depression. Depression in mothers was more strongly linked to a negative effect on daughters in particular, something that has been examined before in past research. One recent study found that mothers passed down mood disorders to their young daughters — and that there were actual visible intergenerational effects on brain structure.

Depression has been shown to be passed down from parent to child in various other ways, as well. In 2013, researchers found that pregnant mothers who were depressed could actually transmit mental illness to their fetuses by changing the babies’ brain development. Interestingly, research has also shown that a father’s depression can have a physical impact on his children, making them more likely to be born prematurely.

Receiving depression treatment during pregnancy is safe and effective, research has shown, and should be taken more seriously due to the negative effects of parental mental illness.

“Our results suggest that diagnoses of parental depression may have a far-reaching effect on child development,” the authors write. “Because parental depression may be more amendable to improvement compared with other influences, such as socioeconomic status, it is worth verifying the present results in independent cohorts. If the associations observed are causal, the results strengthen the case even further for intervention and support among children of affected parents.”

Source: Lee B, et al. JAMA Psychiatry, 2016.