Why epigenetics, mental health matter in typhoon season

(Part 1: Epigenetics and mental health: It’s not just In your head) 

The Philippines is disproportionately impacted by climate disasters made worse by political corruption. This year, typhoon season approaches along with El Niño, which meteorologists say may bring fewer but stronger storms. 

Meanwhile many communities are still recovering from last year’s storms. More than six months after Typhoon Tino, critical infrastructure remains unrepaired. Many in Cebu have had to resort to rebuilding their own homes. 

Emotional repair among survivors also endures as an important but underresourced area of disaster recovery. Much is made of the resilience of Filipinos. And yet this cultural trait can also obscure the reality of deep and unaddressed needs. 

In 2013 after Typhoon Yolanda — one of the strongest typhoons ever recorded and the deadliest to hit the Philippines — more than 80% of survivors experienced mental health challenges. This is much higher than rates of psychological distress after the 2011 Japan earthquake (15%) and higher than the estimated national rate of depression in the Philippines before Yolanda (14.5%). 

This high emotional toll can be explained by pre-existing poverty, unemployment, and inequality, and also by the relentless recurrence of storms. Samar and Leyte are hit by around 15 typhoons every year. Just as recurring storms continue to wear away at infrastructure, they can continue to imprint themselves on survivors’ bodies as well. 

Epigenetic studies show that stress from climate disasters can cause molecular changes that endure long past the storm. 

“For traumatic events like natural disasters, [an epigenetic change called] DNA methylation can capture that stress,” says Dr. Jerry Guintivano, a Filipino-American researcher at the University of North Carolina. 

Some of these epigenetic changes that capture stress affect biological processes associated with mental illness. And if left unaddressed, symptoms can worsen over time. In the case of Yolanda, the World Health Organization reported that more than 1 in 10 survivors still required comprehensive treatment for depression, anxiety, post-traumatic stress disorder (PTSD), and schizophrenia a year after the storm. 

There is growing evidence that these epigenetic changes can also be passed on to future generations. As authors of a 2025 study on epigenetic inheritance wrote: “the effects of traumatic experiences do not end with those directly exposed.”

Take for example the case of Hurricane Maria in Puerto Rico. When it hit in 2017, Maria was the strongest tropical storm of that year, killing 4,600 people and leaving thousands more injured and without homes. 

Women who were pregnant during Hurricane Maria gave birth to children with notable changes in their epigenetic makeup. A 2023 study found 47 types of epigenetic changes in the children, some of them at sites related to serotonin production and PTSD. The children are part of a cohort of 187 mother-child pairs who will be followed for the long-term to assess the health consequences of Hurricane Maria over time. 

Filipino psychiatrist RC Alibudbud suggests that the Philippines might do well to undertake a similar longitudinal study. The Philippines ranked highest in the number of young people with anxiety and negative emotions associated with the climate crisis, according to a  2022 global survey by The Lancet.

While this could be due to widespread awareness, it is also likely due to repeated exposure to climate disasters. Epigenetics shows that this exposure could be direct, indirect through household members, or even biologically inherited from parents and grandparents.  

“The survivors of these events are likely to pass on the impacts of extreme trauma to their children and grandchildren through their genetics,” Oxford scientists explain. “Emotionally through PTSD symptoms and mental disorders, and physically, through stress modifiers in their genes.”

However, the forecast is not all doom and gloom. The epigenetics of trauma may actually serve a positive evolutionary purpose.

In the words of Yale researchers, “These epigenetic marks may enable… enhanced responses to future stressful experiences, a concept known as epigenetic ‘priming.’” 

Dr. Cristine Esquivel-Saldivar, a psychologist with In Touch Community Services, says some of her disaster survivor clients are triggered by rain, thunder, and lightning. This may be an example of priming: if someone feels anxious about rain, perhaps they will take an impending storm more seriously and take precautions to prepare. Then again, they may suffer from paralyzing anxiety any time there is a drizzle. The latter is an example of how epigenetic priming can also lead to mental illness.

Again, hope lies in the science of epigenetics. The molecular imprints associated with mental illness are reversible, and there are non-invasive interventions that can help. 

Over the past 10 years, several studies have shown that psychotherapy is associated with epigenetic changes in people with depression, PTSD, and anxiety. Some of the epigenetic changes include alterations in functions involved with stress response as well as with fear-learning and memory. The molecular changes correlated with a variety of improved symptoms in study participants.

“Psychotherapy… can be conceptualized as an epigenetic intervention,” write Drs. Karla Kroflin and Anthony Zannas. “[It can] beneficially affect the epigenome as part of the therapeutic process.” 

Dr. Esquivel-Saldivar’s therapeutic approach includes helping clients connect their behaviors to past experiences, such as exposure to storms. She also helps them connect their behaviors to their families’ behaviors. 

“Here in the Philippines, you might have four generations together in one household. Gen Zers might see baby boomers having strong reactions to something they also have strong reactions to. We can catch that and help develop coping strategies for people to retool.”

Exposure in intergenerational households is an example of what social worker Patrice Patterson calls “context that is important to getting better.” She explains psychologist Deb Dana’s framework of the “3cs” — connection, context, and choice — to re-establish a sense of safety. Adding context for survivors of trauma and intergenerational trauma brings the previously hidden impacts into conscious awareness.  

As Patterson explains, “This context helps people know ‘I am not broken, I make sense, my symptoms make sense’ based on my experiences and the experiences of those who came before me.”

Dr. Esquivel-Saldivar says that overall, narrative context in therapy can re-establish agency among survivors so they feel less helpless in the face of challenges like climate disasters.

The impact of psychological support like this can go far beyond individual health. 

“Because epigenetic changes can be transmitted across generations,” write Kroflin and Zannas, “Psychotherapy-induced epigenetic modifications may be passed on to subsequent generations, fueling new perspectives on the transgenerational prevention of mental illness.”

Epigenetics can help make the case for increased investment in mental health support for disaster preparedness and recovery, support that could improve mental health for survivors and for future generations. But as always the challenge lies with implementation. In the eight years since the Mental Health Act passed, federal investment in mental health has stayed in the 3-5% range. Only this year has it increased to 7% of the national budget. But even with investment, corruption remains a barrier. 

Hope lies with local government units (LGUs) committed to serving their local communities. Dr. Alibudbud highlights that post-Yolanda, the push to train community health workers and allocate money for psychological support was a positive example of building regional “climate-responsive mental health systems.” He notes that there have been improvements in recent years. 

We can only hope these improvements keep pace with the intensity of the coming storms. – Rappler.com