According to research, almost 5% of younger women aged between 20 and 44 have struggled with major depression, and another 4% of women have experienced minor depression

Major depression affects as many as 16% of reproductive-aged women in the U.S. Yet pregnant women have a higher rate of undiagnosed depression than nonpregnant women, according to a study published in Journal of Women's Health.

At present, new research reports that nearly 5 percent of women between the ages of 20 and 44 have struggled with major depression. And another 4 percent of women in that age group have experienced minor depression.

But none of the group is getting adequate care for the condition. Less than one-third of women with major depression were being treated with antidepressants. For those with minor depression, only 20 percent had been given an antidepressant. Dr. Alexander Butwick et al. said, "Depression impacts women of childbearing years who aren't pregnant.”

"By improving awareness of depression in the reproductive years, we may be able to improve care better before a woman gets pregnant. Women could get appropriate counseling and treatment in place before pregnancy, which may help mitigate depression during pregnancy," the lead author added.

Approximately 13% of women experience major depression during pregnancy, according to the researchers. Depression during pregnancy has been linked to several severe outcomes, including the mother's self-harm or suicide, reduced growth in the baby, preterm birth and low mother-child bonding.

More than half of women who have depression during pregnancy also had suffered from depression before pregnancy, the researchers noted. So getting a treatment plan in place beforehand would be perfect.

About half of U.S. pregnancies are accidental. That's why the study authors wanted to see how many women are dealing with depression during their reproductive years.

"Depression, if uncontrolled, may have an impact on a woman and her pregnancy outcome. If you're aware of a problem beforehand, you have the luxury of time to plan," Butwick said.

The study included data from a nationally representative survey of health and nutritional status in the United States. The data is continuously collected in two-year cycles. For this study, the researchers looked at 2007 to 2014.

Major depression required participants to have five or more depressive symptoms more than half the days in the past two weeks, though minor depression involved fewer than five, according to the study.

The data only has pregnancy status for women aged 20 to 44, so that's the age group targeted by researchers. They excluded women who were pregnant and those who had given birth in the past 12 months.The study finished with 3,705 women of reproductive age. Among them, 5 percent suffered from major depression.

Factors associated with significant depression included having high blood pressure, smoking and having government insurance. The one element with a statistically significant link to minor depression was having a high school education or less. Butwick said these associations shouldn't be considered as risk factors for depression. More study is needed, he added.

Dr. Chris Karampahtsis is a psychiatrist at NYU Winthrop Hospital in Mineola, N.Y., who helps oversee a maternity mental health program. He reviewed the study's findings.

"The big challenge has been that there hasn't been much research in non-pregnant women of childbearing years. This is a particular subset of women that requires focus," he said.