Perinatal mental disorders occur during pregnancy or 12 months after childbirth and are among the most common morbidities during pregnancy. Moreover, they are major contributors to maternal mortality and adverse neonatal, infant, and child outcomes. ¹ In particular, perinatal depression (PD) has a prevalence of 20% and 10-15% in developing and developed countries, respectively, ^{1, 2} and has been associated with an increased risk of preterm birth, miscarriage, foetal growth retardation, and low birth weight. ^{3, 4} Therefore, the fact that it is sometimes underdiagnosed and frequently untreated ⁵ can have consequences for both the mother and the foetus or infant.

In Spain, the prevalence of depressive symptoms reported by Marcos-Najera et al. in 2021 is 10%. ⁶ In another study carried out during the years 2014-2015 through screening with a questionnaire, The Patient Health Questionnaire (PHQ-9), they found a prevalence of moderate-high prenatal depression of 14.8%. ⁷ In this study, those who did not complete the screening were more likely to be immigrants and were not able to read Spanish. In a further study in Spain during the years 2014-2017, they found that the native group presented a lower prevalence of depression (15.2%) than the immigrant group (25.8%). ⁸ In agreement with this, ethnic minorities in Western countries are often exposed to stressors, such as problems arising from lack of social integration, language, and housing, and these factors can affect their mental health. Ethnicity and culture can also determine the inclination of these groups to request help from health services. ⁹ Indeed, the prevalence of antidepressant use during pregnancy ranges between 1.8% and 8.0%, depending on the country and setting. ^{9– 11}

Finally, although depression in pregnancy is recognized as a public health problem, there are few studies on pregnant women undergoing antidepressant treatment. In this context, we aimed to study the prevalence of depression under treatment both in the immigrant and native population in a Health Region of Spain.

In our study, we analysed the prevalence of depression among pregnant women in the Health Region of Lleida between 2012 and 2018. We found a prevalence of 2.5%, and 24% of them received treatment. Similarly, Minguez et al. found a prevalence of use of antidepressant among pregnant women of 3.2%, and 2.7 in the first trimester and in the following ones, respectively. ¹⁴ In our case, no variation in prevalence of depression under treatment was observed over the years. On the contrary, a study in Denmark showed that the rate increased from 0.2% in 1997 to 3.2% in 2010. ¹⁵

We found that pregnant women with depression were older and had a higher BMI. In contrast to our study, Minguez et al. found no significant difference in the use of drugs according to age. ¹⁴ Other studies identified as a risk factor being over 30 ¹⁶ or over 35. ¹⁷ Finally, in some studies, depression has been even related to lower age. ^{18, 19} As for the BMI, the association of depression with obesity is complex because of the mutual influence between these two factors. On the one hand, there is evidence that women with depression have a higher risk of developing obesity ^{20, 21} ; on the other hand, it has also been shown that women with obesity are more likely to develop depressive symptoms during pregnancy and/or in the post-delivery period than women with a normal weight ^{22– 24}

As for ethnic groups, Western European women showed the highest prevalence of depression (2.9%), followed by women from Latin America (2.6%) and Eastern Europe (2.3%). We observed a significantly lower prevalence among women from Africa (0.8%), and from Asia and the Middle East (0.4%). This lower prevalence that we observed in the immigrant population contrasts with another study carried out in Spain. ⁸ Moreover, different results were obtained by a study in Oslo, in which the prevalence found were the following: 8.6% (95% CI: 5.4-11.7) for women from Eastern Europe; 19.5% (12.2-26.8) for women from the Middle East; 17.5% (12.0-22.9) for women from South Asia; and 11.3% (6.1-16.5) for other groups. When running logistic regression models, a significantly higher risk was found for women from the Middle East (OR=2.8, 95% CI 1.3-6.1) and South Asia (OR=2.7, 95% CI 1.3-5.5), in comparison to other minorities and women from Western Europe. ²⁵ Similarly, a study in the UK analysed 7824 women, of which 3514 were British and 4310 South Asian, showing that the South Asians were more predisposed to develop depression than the British (43.3% vs 36.1%, p<0.0001). ²⁶ In our study, the lower prevalence of depression in the immigrant population may be related to problems in accessibility to healthcare because of language and cultural barriers, as it has been referred to in other studies. ²⁷ Another key factor might be represented by the difference in the mean age of pregnant women in the native and immigrant populations. Other factors to consider are differences in the clinical presentation of the disease, with symptoms of somatization that make it difficult to suspect an affective problem. ²⁸ However, the low prevalence of depression in the immigrant population that we found in our study suggests a problem of lack of detection.

The overall estimated mean prevalence of depression is 12.0%, ¹ though some studies report rates as high as 20.0%. ²⁹ However, when focusing on the prevalence among patients receiving pharmacological treatment, the values are notably lower. For example, in a study across 15 countries, ³⁰ the prevalence of selective serotonin reuptake inhibitor (SSRI) use—the most commonly prescribed antidepressants—was found to be 3.0% (95% CI 2.3-3.7). Regionally, pooled prevalence estimates were 1.6% in Europe, 1.3% in Australasia, and 5.5% in North America. This meta-analysis highlights significant regional differences in antidepressant use during pregnancy, likely influenced by variations in prescribing practices, healthcare-seeking behaviours, and the structure of healthcare systems.

Among the prescribed pharmacological classes, 72.4% of the medications belonged to the “Selective serotonin reuptake inhibitors” group, followed by “Selective serotonin-norepinephrine reuptake inhibitors” (11.6%), “Non-selective monoamine reuptake inhibitors” (9.6%), and “Atypical antidepressants” (5.3%). In our study, paroxetine was the most commonly prescribed drug, followed by sertraline, citalopram, and escitalopram. This is noteworthy, given that paroxetine use has been linked to an increased risk of congenital cardiovascular malformations. ³¹ In contrast, sertraline is recommended during pregnancy in several clinical guidelines due to its favorable lactation safety profile. ³² Anderson et al. suggested that certain selective serotonin reuptake inhibitors, including venlafaxine and bupropion, may cause specific adverse effects in newborns, with venlafaxine showing the strongest impact, while escitalopram exhibited the least pronounce. ³¹

The primary limitation of this study is the absence of socioeconomic data for the patients. Numerous studies have reported positive associations between low social support and the occurrence of antenatal depression, antenatal anxiety, and self-harm during pregnancy. Meta-analytic pooled estimates further highlight a significant positive association between low social support and antenatal depression (AOR: 1.2, 95% CI: 1.0, 1.4) as well as antenatal anxiety (AOR: 2.0, 95% CI: 1.3, 2.9). ³³ The main strength of this study lies in its analysis of clinical practice in a large population. Due to the universality of the Spanish healthcare system, all patients have access to healthcare and receive partial coverage for therapeutic prescriptions, ensuring that the data closely reflect real-world clinical information.

Finally, similar to other studies, we found prevalence of depression among pregnant women of 2.5%. Age and weight were the main factors associated with depression. Regarding ethnic groups, the highest prevalence was observed in women from Western Europe, followed by women from Latin America and Eastern Europe. The most prescribed drugs were Selective serotonin reuptake inhibitors, among which paroxetine was the most frequently used. In some ethnic groups, we observed a lower prevalence of pregnant women undergoing antidepressant treatment. This can be attributed to a possible under diagnosis of depression or variations in the therapeutic approach. In conclusion, pregnant women that are older or with higher BMI, or belong to some ethnic groups, may need additional outreach to facilitate assessment and treatment of depression. Further studies are needed to better define the prevalence of depression among pregnant women belonging to ethnic minorities and new public health policies must work in a context of multiculturalism.

This study was approved by the ethics and clinical research committee “Institute for Primary Health Care Research Jordi Gol i Gurina (IDIAPJGol)” under the code 19/196-P, Approved on May 15, 2020. The study was conducted in accordance with the principles of the Declaration of Helsinki. We performed a pseudonymized retrospective descriptive cross-sectional study according to Additional Provision 17.2.d LOPD-GDD for research purposes, without the need to obtain the consent of the data holders. Thus, the consent was waived by the ethics committee. There was a technical and functional separation between the research team and the performer pseudonymization, and data are only accessible to the research team. Technical measures have been taken to prevent re-identification and access by third parties through the CMBD (“Conjunt Minim de Base de Dades”), the E-CAP computerized medical history database, and the Catalan Health Service database.

Not applicable.

DP and LG conceptualised the study, analysed the data, and wrote the first draft of the manuscript; MCS contributed to the design of the study, data management, and manuscript development and review; MO and JS contributed to the design of the study, creation of data bases, and data analysis; LG provided, validated, and helped to interpret pharmacological data; JP conceptualised the study and review of the manuscript draft. All authors read and approved the final manuscript.