Epigenetics and mental health: It’s not just in your head

Kaya mo ‘yan!” (You can do it!) 

This is a phrase we hear often when we need encouragement. 

But, what if we can’t actually do it? What if we’re depressed or anxious and can’t function? Then maybe we’re a disappointment, an embarrassment. Why can’t we just get out of our heads?

This is an example of mental health stigma, something that a 2023 Harvard study found is still widespread in the Philippines. While understanding of mental health increased during the pandemic (along with rising cases of mental illness), stigma remains a barrier. One out of three providers cite shame and fears of being perceived as “weak” or “crazy” as primary reasons that people avoid help that may otherwise be readily available. 

Behind this enduring stigma lies the assumption that mental health struggles are all in our head.

But the science of epigenetics shows a different truth: that people who struggle with depression, anxiety, and post-traumatic stress disorder (PTSD) may actually have molecular changes throughout their bodies. These physical markers show that mental health issues are biological conditions; they can’t be wished away any more than you can will yourself out of diabetes or heart disease. 

Dr. Jerry Guintivano, a psychiatric researcher at the University of North Carolina, says that epigenetics has the potential to show that “none of it is your fault.” According to Guintivano, understanding molecular changes associated with depression, anxiety, and other conditions could lead to a culture shift that destigmatizes mental illness and embraces interventions for mental well-being.

What is epigenetics?

Epigenetics literally means “on top of” your genetics, your genes. As a cross-disciplinary field of scientific study, epigenetics looks at molecular changes that affect how our genes are turned “on” or “off.”

Here’s an analogy: imagine we are all born wearing permanent blue jeans. We can’t take them off because we inherited them from our parents, who inherited them from their parents, and so on. And though they might vary slightly, the perma-jeans are almost exactly the same for every human. 

These perma-jeans are like our genomes. Genomes are our complete set of DNA, which contains our biological genes. Our DNA is 99.9% similar in all humans, and our genes remain more or less the same throughout our lifetimes. 

Now imagine that our perma-jeans can get accessorized. The denim and zipper and pockets stay the same, but on top there may be sequins, or embroidery, or they can have an outer puffy layer to keep you warm if you live in the cold. 

The accessories that live above our perma-jeans alter the look and function of the jeans. Similarly, there are molecular accessories that live above our DNA that can alter functions and phenotypes in our bodies. 

When it comes to development, these molecular accessories are what direct our cells to differentiate into various  tissues like skin, lung, and brain tissue. When it comes to daily life, some of these accessories direct our cells to change bodily functions in response to our environments. 

Scientists say that epigenetic changes may have originally evolved to increase our adaptation to stressful events. While these changes might enhance survival in the short run, they can become maladaptive over time.

When it comes to mental health, stress can leave epigenomic imprints that predispose us to depression, anxiety, and more. These conditions may at times serve adaptive purposes such as helping people withdraw from stressors, or heightening threat detection to avoid recurrent danger. However, these changes become maladaptive when they no longer fit our current environments, such as when they inhibit us from taking care of the ones we love. 

Postpartum depression

Dr. Guintivano specializes in the study of genetic and epigenetic markers that predispose women to postpartum depression (PPD). In the Philippines as a whole, more than 1 out of 5 women may suffer from PPD, with 70% blaming themselves for the condition. 

A common stigma around PPD is that those who experience it aren’t fit to be mothers. They may be seen as disappointments or even embarrassments. 

But in a study of 93 pregnant women, Guintivano found 3 epigenetic markers in the blood cells of women who developed PPD. The presence of these markers predicted which of the study participants would develop PPD with an accuracy of about 80%. 

Guintivano uses the analogy of a jar to illustrate how stress can imprint as an epigenetic predisposition to PPD. Everyone starts with a jar that has their genetic predisposition to PPD at the bottom. This is what we’re born with, part of the .1% of variation in all human DNA. The rest can get filled up over time in reaction to stressful environments, perhaps leading to epigenetic changes like the 3 biomarkers found in his study. Then if we add the process of pregnancy and childbirth, which are themselves extremely stressful events, the jar can overflow, triggering the experience of PPD. 

This jar model shows that if environmental imprints of stress are a main factor in PPD, then environmental reduction of stress should be a key intervention to prevent PPD. This shift in focus away from individual blame to environmental context is perhaps one of the most promising implications of epigenetics for healthcare. Another implication is the opportunity for proactive intervention following early detection. 

“I really am driven by the idea of recognizing early on who’s at high risk,” says Guintivano. “Because none of this is deterministic.”

In the case of postpartum depression, early identification of epigenetic markers could allow time for the mobilization of human infrastructure shown to buffer against PPD. 

“One of the biggest protectors against postpartum depression is a good social support system,” says Guintivano. “You don’t want your lola to just pray. You might bring her, your mom, your brothers, your sisters together and they can watch the baby while you take a nap, and also have them educate each other about postpartum depression because they might all have their stigmas around it. This level of intervention without medication can go far.”

Intervention at the policy level can go even further in creating environments of support. 

A 2019 study showed that PPD services were not routinely provided in rural areas throughout the Philippines, even though PPD affected more than 1 in 10 mothers in these areas. A bill currently in Congress called the Maternal Mental Health Act seeks to address this in government health facilities around the country. It would require psychological screening and counseling in the postpartum period, as well as an increase in training and public education around PPD.

For those diagnosed with PPD, another bill currently in the House would mandate an additional 15 days of paid maternity leave with the option to extend up to one year without pay.

Dr. Guintivano, whose mother is Filipina, hopes to connect his research to Philippine contexts to support increased clinical and policy interventions like these.

As will be explored in the next article in the series, interventions can affect not just individuals struggling with mental health challenges like PPD, but could also affect epigenetic changes across generations on a public health-wide scale. – Rappler.com

(Part 2 on Sunday, May 24: Why epigenetics, mental health matter in typhoon season)