This is the first study to examine the prevalence and correlates of mental disorders and mental health treatment-seeking in a nationally representative sample of pregnant and postpartum women. We highlight four major results: (1) although rates of Axis I psychiatric disorders, including substance use, mood and anxiety disorders, are high in women of childbearing age regardless of pregnancy status, pregnancy per se is not associated with an increased risk of new onset or recurrence of mental disorders, and is associated with lower rates of substance use, except illicit drug use, and substance use disorders; (2) the risk of major depressive disorder may be increased during the postpartum period; (3) younger age, not being married, exposure to traumatic or stressful life events in last 12 months, pregnancy complications, and overall poor health increase the risk of mental disorders in past-year pregnant women; and 4) treatment rates among pregnant women with psychiatric disorders are very low.
Although high rates of psychopathology have been reported in clinical samples of pregnant and postpartum women,40, 41, 61–64
the specific contribution of pregnancy to the prevalence of psychiatric disorders in women of childbearing age had not been previously examined. In our study, the overall 12-month rate of psychiatric disorders in pregnant and postpartum women was high, but no differences were found in the overall prevalence of psychiatric disorders between past-year pregnant and postpartum and non-pregnant women, except for the prevalence of substance use disorders, which was lower in past year pregnant and postpartum women than in non-pregnant women of childbearing age. Our results are in accord with most3, 5, 7, 8, 44, 65
, although not all,47
studies derived from clinical samples, but are important because they extend them to the general population. Clinical studies have suggested that trimester of pregnancy affects the rates of psychiatric symptoms, with exacerbation of symptoms in the first two trimesters of pregnancy, and attenuation of symptoms in the third.80
The NESARC did not collect data on month of pregnancy at interview. Including only women during their first, second or third trimester of pregnancy, might have resulted in higher or lower estimates, according to trimester, of the prevalence of mental disorders among pregnant women than the ones reported here. Our results on all pregnant women, regardless of trimester, provide a more accurate overall estimate of the prevalence of psychiatric disorders during this entire critical period. Nevertheless, the high prevalence of psychiatric disorders in pregnant women stresses the need for continued work to identify the causes and develop effective treatments for mental disorders among pregnant and postpartum women.
Past-year pregnant and postpartum women were significantly less likely than non-pregnant women to use any substance, except illicit drugs, which were slightly but not significantly less likely to be used among past-year pregnant and postpartum women. Data from the 2006 National Survey on Drug Use and Health (NSDUH) reports significantly lower rates of substance use, including illicit drugs, among pregnant women compared to non-pregnant women.66
However, rates of substance use by pregnant women overall in the NSDUH were lower than the rates reported in our sample. This discrepancy may be due to differences between the NSDUH and our study in the alcohol consumption and substance use measures and the timeframe for reporting use of these substances (30 days in the NSDUH and last 12 months in the NESARC). Moreover, the test-test reliability and validity of the NSDUH alcohol consumption and drug use measures have not been reported, so differences in psychometric properties of the measures in the two surveys could also contribute to a difference in results. Nonetheless, substance use by pregnant women is a leading preventable cause of mental, physical, and psychological problems in infants and children.13, 14, 37, 38, 39
Special focus should be given to developing effective screening and intervention efforts to assist pregnant and postpartum women to reduce substance abuse, and to evaluating the effectiveness of current treatment programs and barriers to treatment for pregnant substance users.
Although the overall prevalence of psychiatric disorders appears to be similar among currently pregnant, postpartum women and non-pregnant women, an important exception was the elevated risk of major depressive disorder during the postpartum period. Biological (e.g., hormonal) as well as psychological and social role changes associated with childbirth may increase the risk of major depressive disorder during postpartum. Furthermore, women with psychiatric illness who become pregnant may discontinue their psychiatric medication for fear of prenatal exposure to these agents, therefore increasing the risk of depressive relapse during pregnancy or the puerperium.64
Our finding is consistent with most previous studies,2–5, 9
although a lack of increase in prevalence in major depressive disorder during this period has also been reported.7, 8
Past negative results may have been due to differences in the diagnostic criteria, the timing of the assessments, limited sample sizes, or use of convenience, rather than population-based, samples. Our findings underscore the need for systematic screening and treatment of postpartum women to ensure their health and the health of their offspring.
Risk factors for psychiatric disorders and substance use among pregnant women are consistent with those identified in the general population67–74
and clinical simples of pregnant women. 22, 41, 42, 45, 49, 50, 66, 75
The odds of psychiatric morbidity were greater among women who are younger (ages 18–25); widowed, separated or divorced; reported recent loss of a romantic relationship, trauma, or victimization; among those with more stressful life events; and among those with poor or fair overall health. Our study extends previous findings by documenting that pregnancy complications are also associated with significantly higher risk of psychiatric morbidity in pregnant women. Identification of these groups at increased risk of psychiatric disorders should help alert all clinicians who treat pregnant and postpartum women (and their children) and to focus targeted prevention and early treatment interventions in these populations.
Pregnant women with psychiatric disorders seldom reported having sought mental health treatment. Consistent with prior community surveys, most women with a current psychiatric disorder did not receive any mental health care in the 12-months prior to the survey 76
. We found that this result holds regardless of pregnancy status, even when adjusting for sociodemographic factors. Furthermore, past-year pregnant women with past-year mood disorders had lower treatment rates than non-pregnant women. This observation is consistent with a recent report that pregnant women are less likely than non-pregnant women to receive inpatient or outpatient psychiatric treatment9
and that mental health symptoms and diagnoses are significantly undetected and underrecorded in pregnant women who receive prenatal care in obstetrics clinics.46
Our analyses suggest that differences in service use are unlikely to be due to lower need (i.e., lower prevalence), but rather to a decreased ability to obtain care. This important, previously undetected health care disparity is even more striking because most women of childbearing age access the health care system during their pregnancy or postpartum.78
Their failure to receive psychiatric treatment suggests the existence of important barriers to mental health care for this population.79
Patients and health care providers may view psychiatric symptoms as a normative response to the physiological and psychosocial changes during this period. Based on our results, such reactions may be mistaken and may interfere with recognition and treatment of psychiatric disorders among pregnant and postpartum women.21, 46
Educational campaigns targeting women, their caretakers, and primary care physicians may be needed to increase recognition of psychiatric disorders among pregnant women. Mental health screening during routine prenatal and obstetrical care may improve the detection of psychiatric disorders. 46
Dilemmas about the treatment of psychiatric disorders during pregnancy and puerperium may discourage women from seeking psychiatric treatment during this period.80
Development and testing of empirically-validated treatments for pregnant women that are safe for the fetuses may increase rates of treatment-seeking.81–84
Competing medical demands, such as those directly related to pregnancy, postpartum and pediatric care, other family, social and work obligations or simply fatigue may interfere with patients’ ability to attend appointments. Treatment models that are more patient-centered may be needed to facilitate mental health treatment of this population.85
Those models may include modifications already in place for the treatment of other populations, such as delivery of psychotherapy over the telephone or extended clinic hours.86
Our results should be interpreted in the context of the following limitations. First, information on pregnancy status was based on self-report and not confirmed by pregnancy test. Second, because the NESARC sample only included individuals 18 years and older, information was unavailable on adolescents, who may be at increased risk of developing psychiatric disorders during pregnancy, although rates of adolescent pregnancy have recently declined.87
. Third, although NESARC is the largest US psychiatric epidemiological survey ever conducted, our power to detect subgroup differences in the prevalence of rare mental disorders, e.g., psychotic disorders, is limited.
Fourth, the assessment of 12-month symptoms in currently pregnant women may have included women who were early in pregnancy, and therefore reporting symptoms largely, or entirely from months prior to pregnancy. This would result in reducing the apparent differences in prevalence between the non-pregnant and the pregnant women samples. However, most of the findings held when analyzing those two groups separately. Fifth, the NESARC did not specifically assess the amount of obstetrical care received by pregnant and recent-postpartum women, information that would be helpful to add to future large-scale epidemiologic studies. Sixth, the cross sectional design does not permit distinguishing the effects of pregnancy selection from pregnancy itself on rates of psychiatric disorder and treatment. In other words, if women without prior history of psychopathology were more likely to become pregnant than those with psychopathology, selection bias could mask an effect of pregnancy on increased rates of psychiatric disorders in pregnant women. However, by controlling by prior psychopathology, our analyses should have minimized this possibility, at least to some extent. Prospective studies that compare pregnant women with women who attempt but fail to become pregnant may also be biased by potential psychopathology related to pregnancy failure.
Seventh, the NESARC did not collect data on month of pregnancy, period since delivery, use of psychotropic medication during pregnancy or puerperium, pregnancy outcomes or specific complications. It is possible that some of the women included in the postpartum group may have had a miscarriage or abortion. However, our data suggest that women with pregnancy complications have a greater prevalence of psychiatric disorders than other pregnant women. Exclusion of women with a miscarriage or abortion from the analyses would have resulted in lower estimates of mental disorders than the ones reported here, suggesting that our analyses do not underestimate the prevalence of psychiatric disorders among pregnant women. Eighth, information on substance use and substance use disorders was based on self-report and not confirmed by objective methods. Some discrepancies have been found between self-reported and objectively measured rates of drug use in pregnant women in antenatal care 88
Finally, our results rely on DSM-IV Axis I categories, a dichotomous model of psychopathology. Continuous models of psychopathology, currently being considered for DSM-V, may have provided different results.
Despite these limitations, the NESARC constitutes the largest nationally representative survey to date to include information on psychiatric disorders in pregnant women. Pregnancy is traditionally viewed as a stressful period that may provoke mental illness. 89
However, with the exception of major depressive disorder among postpartum women, the prevalence of psychiatric disorders is not significantly higher in pregnant women and postpartum women than in non-pregnant women of childbearing age. It is possible that the clinical impression of elevated rates of mental disorders among pregnant women is explained by the higher contact of pregnant women with some aspects of the health care system, in this age period, compared to their non-pregnant counterparts, whose disorders are therefore underestimated. In this study, groups of pregnant women with particularly high prevalence of psychopathology were identified (i.e. pregnant women aged 18–25, living without a partner, widowed, separated, divorced, and never married, pregnant women who experienced pregnancy complications, stressful life events, and trauma or victimization, and pregnant women with overall poor health). These more vulnerable groups should be targeted for prevention, assessment, and intervention efforts. Low rates of mental health service use were identified in this population. Given the critical importance of this life period for mothers and their offspring, urgent action is needed to increase detection and treatment of psychiatric disorders among pregnant and postpartum women in the United States.