Olga Valverde Granados (Cádiz, 1965) is a researcher and a professor at the Department of Medicine and Life Sciences (MELIS) at Pompeu Fabra University (UPF). She has recently received a grant of 200,000 euros from the La Marató de 3Cat Foundation in the framework of the 2023 edition dedicated to sexual and reproductive health. Entitled Interaction between endocannabinoids and oxytocin in the pathophysiology of perinatal depression (INDOOR), the research led by Valverde studies how certain neuronal systems influence depression during pregnancy (known as perinatal depression) and the subsequent effects this disorder has on the patient.

A graduate in Medicine and Surgery from the University of Cádiz, Valverde also holds a PhD in Neuroscience from the University of Cádiz and in Pharmacy from Paris Descartes University. She joined the UPF Faculty of Health and Life Sciences in 1998. She is currently a full professor of Psychobiology and directs the Neurobiology of Behaviour research group (GReNeC) of the Department of Experimental and Health Sciences, which focuses its research lines on the study of the neurobiological bases of affective disorders, drug abuse addiction, and the study of pain.

Why is it important to study the biological bases of perinatal depression?

Women’s mental health has historically been disregarded. This means that it is not given sufficient importance or allocated the necessary financial and human resources. Diseases like perinatal depression or other exclusively female disorders, such as endometriosis, have often been considered ‘second-class diseases’. Perinatal depression has been under-researched, because it was regarded as an extension of depression. We now know that it is a different entity, with specific characteristics that require studying in depth.

How widespread is this disorder? Quantitatively, can an analogy be made with another disease in order to get an idea of its scope?

It is estimated to affect between 10 and 15% of pregnant or postpartum women, although this figure may be higher, since it is often undiagnosed. During the covid-19 pandemic, this percentage increased significantly, probably due to the isolation and fear that many women suffered, not only because of the possible impact of the virus on their pregnancy, but also because of the uncertainty of how they would be attended to during childbirth.

In addition, the fact that there is still a stigma attached to mental health contributes to this lack of diagnosis. Many women may feel embarrassed or afraid of being judged for admitting that they are not fully enjoying maternity, thus delaying access to appropriate treatment. This means that the disorder remains under-identified, despite its significant impact on the quality of life of the women concerned and on the development of the newborn.

“Perinatal depression affects between 10 and 15% of women, but it often goes undiagnosed due to the associated stigma”

What strategies do you consider key in order to reduce the stigma attached to this depression?

It is important to demonstrate that perinatal depression has a biological fundament thanks to scientific evidence that refutes the idea that it depends on the person’s will. In addition, health professionals and politicians should use clear and accessible language to explain that this disorder is the result of complex biological and social factors. It is also essential to raise the awareness of society with regard to the impact of the disease both on the mother and on the development of the baby, in order to give it the visibility it deserves and promote public policies that prioritize mental health.

Why do you think this kind of depression hasn’t been sufficiently investigated? Is there a gender bias?

There are several reasons. On the one hand, the experimental models we use to study depression in animals do not always reproduce the hormonal and neurological changes that occur during gestation reliably. On the other hand, there is a gender bias in science: historically, biomedical studies have been conducted with men as the main model. Lastly, purely female diseases, like perinatal depression, are often relegated to second place.

We have come to terms with the fact that we women are resilient and we have to endure everything: painful menstruation, the pain of childbirth, and so on, but it shouldn’t be like that.

How is perinatal depression diagnosed?

Diagnosis is usually based on the symptoms that the mother explains to her gynaecologist or GP, such as episodes of prolonged sadness, a lack of energy or difficulty bonding with the baby.

These professionals refer the patient to a psychiatric specialist, where more specific tests are undertaken: the patient’s complete medical history is documented, including her personal and family history, and specific tests are conducted to identify emotional disorders such as depression. Despite this, today we depend greatly on what the patient tells us, and this can lead to many cases not being detected in time. In fact, the tests are standardized and are very useful for detecting perinatal depression and assessing patient well-being during gestation. In our project we will use some of these diagnostic tools, although it won’t be me applying them, but the psychiatrist who is on the team.

What impact can this disorder have on the baby’s neural development and, therefore, on the family environment?

Perinatal depression can have a negative effect on the bond between mother and child, a fundamental aspect during the first months and years of the baby’s life. This bond starts to form before childbirth and is especially crucial during the first thousand days of the child’s development. During this stage, the baby depends almost exclusively on its mother, especially during the first months, when bonding is essential for its well-being and development.

“Perinatal depression can have a negative effect on the bond between mother and child, a fundamental aspect during the first months and years of the baby’s life”

The function of this bond is not just an affective one; it also contributes to the baby’s cognitive and emotional development. When this bond is disrupted, the baby’s brain might not develop appropriately, which can affect its learning ability, its emotional relationships, and even its future mental health.

In our project, we study this impact in both experimental and in human models. We are working with data from the mother and the baby: we follow the bond between them for some time and we interview the mother to find out how she feels. We also evaluate the baby’s psychomotor development through trials and tests to see if the fact that the mother is depressed affects the child’s development. We typically follow this process for six months, though we can make adjustments as needed.

What role do the oxytocin and endocannabinoid systems play in this depression?

These are two key systems for the regulation of emotions, affective bonding and motivation. Oxytocin, for example, is essential during childbirth and postpartum, as it fosters uterine contractions, breast milk and the bond between mother and child. Endocannabinoids, for their part, modulate many brain functions and help regulate oxytocin. This endocannabinoid system acts as a general modulator of the brain, influencing several neurotransmitters, which gives it a central role in the regulation of behaviour and emotions.

These systems do not act independently but are connected, and it is this interaction that we are interested in exploring. For example, we know that the release of oxytocin during childbirth and postpartum facilitates the emotional bond between mother and child, but if this system is altered, the bond may not develop properly. Similarly, endocannabinoids play an important role in regulating stress responses and the ability to adapt, which are key aspects during postpartum. We want to investigate how these alterations might contribute to the development of perinatal depression and whether we can identify biomarkers that signal these disruptions, thus paving the way for possible therapeutic strategies.

What therapeutic breakthroughs do you hope to achieve with this project?

Our main goal is to generate knowledge on the biological mechanisms of this depression and identify biomarkers to allow its early diagnosis. This could help anticipate the disorder before the onset, or develop more personalized therapies in the future. However, we must be cautious: we are still in the early stages, and the leap from possessing this knowledge to designing new treatments can require years of research.

“We want to identify biomarkers for early diagnosis and head towards personalized therapies”

However, this is beyond the scope of this particular project and would require future research focusing rather on the development of specific treatments. For the time being, our priority is to lay the groundwork for improving the diagnosis and understanding of this condition.

How does this €200,000 grant from the La Marató Foundation contribute to your research?

This aid is crucial to move the project forward. Scientific research is very costly, both insofar as the materials and the experimental models, and the necessary human resources. Without this support, we would not have been able to launch the project under the current conditions. In addition, the funding of the La Marató Foundation not only allows us to advance in our research, but it also gives the project great public visibility and helps to attract further scientific and social support and interest.