Over 17 million adults in the United States had at least one major depressive episode in 2017 (National Institute of Mental Health, 2019). Globally, more than 264 million people of all ages experience depression (World Health Organization, 2020).

In the United States, major depressive episodes are more common among adult women (8.7%) than adult men (5.3%). At 13.1%, young adults, aged 18-25, had the highest rate of major depressive episodes (National Institute of Mental Health, 2019).

As our understanding of mental health increases, we are beginning to look at how the environment of our parents and grandparents influences our own health and the health of our offspring. This knowledge is based on new research that investigates the epigenetic processes which regulate how the environment affects the expression of genes that relate to mental health generally and to depression in particular (Sun et al., 2013).

As our understanding of mental health increases, we are beginning to look at how the environment of our parents and grandparents influences our own health and the health of our offspring.

Environmental Impacts of Depression: Past and Present

Mental illness is incredibly complex and is influenced by a host of biological, chemical, and environmental factors. Depression, for example, is much more than low mood, negative thoughts, or a chemical imbalance in the brain. When we look at the biological component of depression, we see just how powerfully environment may determine our vulnerability to developing depression and how these environmental effects occur and accumulate over the generations.

We know childhood abuse and neglect can have lifelong impacts on the health and well-being of the child. But what about looking into the environment of our ancestors? We are beginning to understand how our parents’ and grandparents’ environment impacts our own and our children’s mental health.

Epigenetics, in its simplest meaning, refers to the stable changes in gene expression without modification of the DNA sequence. In the context of depression, these changes are often triggered by severe stress, and they can result in an increased vulnerability in the brain’s limbic regions (Nestler, 2014). The limbic regions of the brain are implicated in depression, as they are involved in emotion regulation, self-preservation, and the desire to procreate (Pandya et al., 2012). These changes in gene expression can be passed down from parents to offspring. However, the exact process of how this happens is still largely mysterious (Kaneshiro et al., 2019).

While the mechanism of transmission is not clear, the results of environmental exposure to risk factors for depression are measurable. We now know that the stress of our parents and grandparents can cause increased vulnerability to depression in ourselves and our children. The vulnerability to depression can be passed down through generations. This is true even though we may not have experienced early abuse, trauma, or neglect.

Change in Both Directions: How Environment Can Nurture

Epigenetic changes can also occur because of positive experiences such as supportive, healthy relationships and learning opportunities. Good physical health also influences gene expression in a positive way. Having access to nutritious food and a healthy lifestyle may also have a protective effect on mental health.

Even in adulthood, our brain continually changes with experience. For example, chronic anxiety resulting from early adverse childhood experiences can be improved by stress-reduction interventions (Hölzel et al., 2010). For adults, living in a healthy environment without prolonged exposure to severe stress can have a real impact on increasing resilience and reducing a person’s vulnerability to developing a mental health issue.

If we provide a healthy, nurturing environment with supportive relationships for our children, we can improve their resilience against developing depression. A healthy diet and exercise are included as part of an optimal environment for children. (According to researchers, a healthy diet, especially for growing infants and children, does not mean a fat-free diet. Fat is essential for neurological development and brain function (Milner & Allison, 1999).)

Therapy Can Improve Resilience

Part of moving toward a healthy lifestyle can include working with a therapist who incorporates cognitive behavioral therapy (CBT). CBT is an individualized process that has been shown to be effective for reducing stress, anxiety, and depression. CBT works on negative and unrealistic thought patterns and unhelpful behaviors. Additionally, therapy is a supportive relationship that allows for the healing of underlying issues that may be causing distress. Therapy and CBT can lead to improvements in mood and reduction in stress that will reduce anxiety and, over time, lead to improvements in brain areas associated with depression.

In summation, our environment, even the environment of our parents and grandparents, has an important impact on our mental health. It is important to understand that when you take care of yourself and your children, you are not only improving your own health—you may also be improving the lives and health of future generations who have not even been born yet.

References:

1. Depression. (2020, January 30). World Health Organization (WHO). Retrieved from https://www.who.int/news-room/fact-sheets/detail/depression
2. Hölzel, B. K., Carmody, J., Evans, K. C., Hoge, E. A., Dusek, J. A., Morgan, L., Pitman, R. K., & Lazar, S. W. (2010). Stress reduction correlates with structural changes in the amygdala. Social Cognitive and Affective Neuroscience, 5(1), 11-17. doi: 10.1093/scan/nsp034
3. Kaneshiro, K. R., Rechtsteiner, A., & Strome, S. (2019, March 20). Sperm-inherited H3K27me3 impacts offspring transcription and development in C. elegans. Nature Communications, 10(1271). Retrieved from https://www.nature.com/articles/s41467-019-09141-w
4. Major depression. (2019). National Institute of Mental Health (NIMH). Retrieved from https://www.nimh.nih.gov/health/statistics/major-depression.shtml
5. Milner, J. A., & Allison, R. G. (1999). The role of dietary fat in child nutrition and development: Summary of an ASNS workshop. The Journal of Nutrition, 129(11), 2094-2105. doi: 10.1093/jn/129.11.2094
6. Nestler, E. J. (2014). Epigenetic mechanisms of depression. JAMA Psychiatry, 71(4), 454-456. doi: 10.1001/jamapsychiatry.2013.4291
7. Pandya, M., Altinay, M., Malone, D. A., & Anand, A. (2012). Where in the brain is depression?. Current Psychiatry Reports, 14(6), 634-642. doi: 10.1007/s11920-012-0322-7
8. Sun, H., Kennedy, P. J., & Nestler, E. J. (2013). Epigenetics of the depressed brain: Role of histone acetylation and methylation. Neuropsychopharmacology, 38(1), 124-137. doi: 10.1038/npp.2012.73

Many might assume that the intergenerational transmission of trauma from parent to child occurs through abuse or neglect, but this is not always the case.

Trauma can also be passed on through changes in gene expression. This is known as the epigenetic transmission of trauma. Epigenetics is understood as changes in gene function that are heritable and not associated with changes in one’s DNA sequence (Dupont, Armant, & Brenner, 2009). It is thought that epigenetic changes can occur as a result of extreme stress, such as in the case of parents with histories of trauma.

Heritability of Trauma

Research with children of Holocaust survivors has indicated that children can inherit the traumatic memories of their parents. The evidence is so compelling that some have argued children can inherit the unconscious minds of their parents. Some children of Holocaust survivors have even been known to have genocide-themed nightmares. Although it can be argued the children receive Holocaust imagery through shared stories and narratives, it does not explain their increased vulnerability to stress-related diagnoses such as complex trauma (C-PTSD) and posttraumatic stress (PTSD).

While may be more difficult to prove the inheritance of traumatic memories, we do know that psychological stress can affect gene expression patterns via the nervous system.

While may be more difficult to prove the inheritance of traumatic memories, we do know that psychological stress can affect gene expression patterns via the nervous system. It may be that the disposition to develop PTSD and C-PTSD is passed down through an epigenetic route (Kellermann, 2013).

When Symptoms Occur Without a History of Trauma

It is important to understand that trauma can be inherited independently of difficult family circumstances. A child can develop anxiety, depression, or other stress-related issues such as PTSD as a result of an inherited vulnerability rather than direct trauma.

Research has shown that secure mother-child attachment is key for childhood development (Meins, Bureau, & Fernyhough, 2018). A recent study shows that “good-enough” parenting is adequate for a child to develop a secure attachment to its mother. What this means is that perfect parenting is not required for the child to grow up securely attached, a state that is associated with the best outcomes for mental health (Lehigh University, 2019).

The research has two sides. On one, the research shows us that we do not require perfect parenting and a stress-free environment to be secure and healthy. The flip side of this research is that some children will inherit trauma even with a gentle upbringing. In these cases, a child can inherit symptoms of trauma, including nightmares and anxiety, even without being exposed to trauma.

Can Epigenetic Changes Lead to Positive Outcomes?

While the news that trauma can be passed down despite good parenting may sound disheartening, epigenetics also creates changes in a positive way as well. When we have good nutrition and are raised in a nurturing and loving environment, over generations, epigenetic changes can also occur for the better. Researchers investigating epigenetics in animal models have found that rat pups with mothers who lick and groom them often are more likely to grow up to be calm, while pups who are not groomed frequently by their mothers may grow up to be anxious (Kirkpatrick, 2017).

What we know from epigenetic research as it relates to the intergenerational transmission of trauma is that we can have at least some influence on our children’s ability to be calm and resilient to stress. By providing a loving and nurturing environment for them, we can diminish the intensity of inherited trauma. Each succeeding generation can whittle away at the effects of trauma through consistent nurturing and loving parenting. Trauma does not have to continue from one generation to the next.

References:

1. Dupont, C., Armant, D. R., & Brenner, C. A. (2009). Epigenetics: Definition, mechanisms and clinical perspective. Seminars in Reproductive Medicine, 27(5), 351-357. doi: 10.1055/s-0029-1237423
2. Kellermann, N. P. (2013). Epigenetic transmission of Holocaust trauma: Can nightmares be inherited?. The Israel Journal of Psychiatry and Related Sciences, 50(1), 33-39. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/24029109
3. Kirkpatrick, B. (2017, December 12). Cuddling can leave positive epigenetic traces on your baby’s DNA. Retrieved from https://www.whatisepigenetics.com/cuddling-can-leave-positive-epigenetic-traces-babys-dna
4. Lehigh University. (2019, May 8). ‘Good enough’ parenting is good enough, study finds. ScienceDaily. Retrieved from https://www.sciencedaily.com/releases/2019/05/190508134511.htm
5. Meins, E., Bureau, J. F., & Fernyhough, C. (2018). Mother–child attachment from infancy to the preschool years: Predicting security and stability. Child Development, 89(3), 1,022-1,038. doi: 10.1111/cdev.12778

I had an eye-opening insight during a recent training class. We were talking about the #MeToo movement and trauma that carries forward from one generation to the next. It suddenly struck me that sexual abuse and violence against women was a trauma all women bear. When I shared my newfound wisdom, many of the women in the class nodded and said something like, “No, duh!”

I could have felt embarrassed because I hadn’t understood the depth of the #MeToo movement and the impact that sexual assault has on women as a group. Instead, I felt even more connected to the women in the room. If we haven’t been abused ourselves, chances are we know someone who has. If that person is our mother, our grandmother, or our great-grandmother, we may hold the impact of that trauma in our own bodies.

How Common Is Abuse of Women?

According to the World Health Organization (WHO), 35% of women around the world have been physically or sexually abused at some point in their life. Risk factors include low income, less education, fewer job opportunities, and living in communities that value men more than women.

If you are a woman of color, your odds of being abused go up. According to the Department of Justice (DOJ), black women are 35% more likely than white women to experience violence at the hands of an intimate partner.

The WHO and DOJ studies don’t include emotional abuse or childhood emotional neglect, so I have to assume the problem is worse than the statistics show.

What Is Intergenerational Trauma?

How can abuse that happened to someone else affect us? Studies have shown that when you have a traumatic experience, it can alter your body chemistry and even change your genes. As a result, the stress from traumatic events or being sexually assaulted or abused can be passed down from one generation to the next.How can abuse that happened to someone else affect us? Studies have shown that when you have a traumatic experience, it can alter your body chemistry and even change your genes.

Rachel Yehuda, PhD, director of the Traumatic Stress Studies Division at the Mount Sinai School of Medicine, studied the impact of stress on people who survived the Holocaust and 9/11. As part of her study, she looked at whether the survivors passed the stress down to their children. When the environment turns a gene on or off, it is called an epigenetic change. Dr. Yehuda found survivors of both 9/11 and the Holocaust passed these changes on to their children.

These traumatic events didn’t just affect the survivors. Dr. Yehuda found that trauma actually changed their children’s genes. The children of survivors showed the same biological and emotional effects of stress from the trauma. They had lower levels of the hormone cortisol, which helps the body manage stress. As a result, they were more likely to have posttraumatic stress disorder (PTSD) and anxiety. The children’s bodies were affected by trauma even though they didn’t directly experience the traumatic event.

The Impact of Violence Against Women Across Generations

Today, women continue to be the victims of sexual and physical violence. In the United States, we live in a male-dominated society where women often have less power. Having less power can increase one’s risk of being abused.

Recent headlines about Harvey Weinstein, Bill Cosby, and other famous men who have been charged or convicted of sexual abuse are only part of the story. It’s not just high-profile cases or ultra-powerful men. One in four women is sexually harassed or assaulted in the military. They are raped on college campuses—23% of female undergraduates report being raped. One in four women in the United States is severely abused by an intimate partner. According to a new study, 81% of women reported they were sexually harassed on the job.

Women who feel helpless in the face of abuse pass that trauma and stress down to future generations.

In this country, women of color have even less power than white women do. Because women of color are a minority, they are often more vulnerable to abuse. Over the course of history, many generations of women of color have lived through sexual bullying, assault, and abuse. Even today, they may be ignored if they choose to say “no” or report the abuse. Women who feel helpless in the face of abuse pass that trauma and stress down to future generations.

Healing and Reason for Hope

The good news, as Dr. Yehuda explains, is that inherited changes work both ways. When we learn how to soothe and manage the symptoms and stress of trauma, we pass that healing down. Even if we’ve experienced trauma, we can create change when we learn how to self-soothe. And our children may be stronger for it.

That being said, self-soothing doesn’t come easily to everyone. It’s hard to manage stress if your body is sounding an alarm even when there’s no danger. This overactive stress response happens for some people who have experienced trauma. We now know it can also occur if your parent was traumatized. Trauma therapy can help you learn how to manage emotions and work through trauma in a safe, supportive environment. You learn tactics that teach your body to return to its ideal level of arousal. When your body learns it’s not constantly under attack, you begin to feel less stressed. If you feel you could benefit from trauma therapy, start your search for a therapist here.

Self-soothing strategies go a long way toward helping you manage the stress that comes with trauma. Learning to self-soothe could also help future generations by supporting genetic changes that make it easier to thrive. But if racism, bigotry, and violence against women and minorities continues, the trauma will also continue to affect victims, survivors, and their children. If we don’t make and create change, the legacy of trauma will continue for future generations of women. It’s time for all of us to do things differently.

References:

1. Campus sexual violence: Statistics. (n.d.) RAINN. Retrieved from https://www.rainn.org/statistics/campus-sexual-violence
2. Chatterjee, R. (2018, February 21). A new survey finds 81 percent of women have experienced sexual harassment. NPR. Retrieved from https://www.npr.org/sections/thetwo-way/2018/02/21/587671849/a-new-survey-finds-eighty-percent-of-women-have-experienced-sexual-harassment
3. Military sexual assault fact sheet. (n.d.) Protect Our Defenders. Retrieved from https://www.protectourdefenders.com/factsheet
4. Rodriguez, T. (2015, March 1). Descendants of holocaust survivors have altered stress hormones. Retrieved from https://www.scientificamerican.com/article/descendants-of-holocaust-survivors-have-altered-stress-hormones
5. Statistics. (n.d.). National Coalition Against Domestic Violence. Retrieved from https://ncadv.org/statistics
6. Tippett, K. (2015, July 30). How trauma and resilience cross generations. Retrieved from https://onbeing.org/programs/rachel-yehuda-how-trauma-and-resilience-cross-generations
7. Violence against women. (2017, November 29). World Health Organization. Retrieved from http://www.who.int/news-room/fact-sheets/detail/violence-against-women
8. Women of color network facts & stats: Domestic violence in communities of color. (2006). Retrieved from https://www.doj.state.or.us/wp-content/uploads/2017/08/women_of_color_network_facts_domestic_violence_2006.pdf

Many of us learned in high school biology class that genetic traits are passed down to us from our parents. We were taught that we have brown, blue, or green eyes because a parent did, we’re thin or fat because a parent was, and so on. Recent research expands this idea in a way that would have seemed inconceivable a few decades ago. We know the traits we pass down to our children can not only change based on our life experience. But we also know we can continue to alter our children’s pattern of genetic activity after they’re born. This area of genetics research is called epigenetics. It’s the study of alterations in gene function caused by changes in gene expression rather than in the genetic code.

This could all seem a bit disheartening to those of us dealing with anxiety, depression, anger issues, or other mental health concerns. If we’re depressed because of our parents’ experiences or how they treated us when we were babies, what hope is there for us? But if we couple epigenetics with research into cognitive behavioral therapy and neuroplasticity (the brain’s ability to form new neurons and glial cells and forge new connections), we have reason to be hopeful.

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In 2010, scientists at the University of Copenhagen fed male rats a diet high in fat and then watched as their offspring gained more weight than the babies of rats fed a regular diet. If traditional theories about genetics had been true, the diet of a rat’s parent shouldn’t have affected the weight of their offspring. The old thinking about genetics—that either you’re born with a gene that predisposes you to obesity or you’re not, and nothing you do in your life changes what gene you pass onto your children—is, according to studies like the Copenhagen one, incorrect.

To discover how gene alteration in rats occurs, scientists studied their sperm. “The genes in sperm cells are regulated by swarms of molecules, so-called epigenetic factors. These molecules can respond to environmental influences by silencing some genes and activating others as needed” (Zimmer, 2015). The research suggests the male rats were handing down epigenetic factors to their offspring.

A 2011 study at the University of Wisconsin showed that “when parents are under emotional, financial, or other forms of stress, it can alter their children’s patterns of genetic activity at least through adolescence and perhaps longer. And since some of the altered genes shape brain development, the effects of parental stress might permanently wire themselves into children’s brains” (Begley, 2011).

It was an earlier 2004 study that showed us how parents can alter a baby’s genes by their behavior toward them. Another rat study, this time at McGill University, revealed that when a mother rat licks and grooms her offspring, “it activates a gene that makes a receptor for stress hormones in the baby rats’ brains, which causes more receptors to be produced, which causes fewer stress hormones.” Thus, the offspring are more “well-adjusted, curious, and mellow” as adults (Begley, 2011).

So, the question becomes: If our parent’ lives before we’re born and their treatment of us when we’re children can have a huge effect on our mental and physical health as adults, what can we do about it if we, as adults, are suffering the consequences? Whether we’re dealing with childhood trauma, anxiety, or another mental health issue, believing so much of our personality is baked-in can be, well, depressing.

Learning more about epigenetics and neuroplasticity gives us a reason to strive to be healthier and happier people.

This brings us to another fascinating area of research: neuroplasticity and cognitive behavioral therapy (CBT). According to a study published in Translational Psychiatry in 2016, “patients with anxiety disorders exhibit excessive neural reactivity in the amygdala” and there is “compelling evidence that CBT for a common anxiety disorder simultaneously changes the physical structure and neurofunctional response of the amygdala” (Månsson, 2016).

This is good news for those of us who just got discouraged reading about epigenetics. CBT is the most widely used evidence-based psychological treatment. It focuses on patterns in cognition, coping strategies, and emotional regulation. CBT subjects learn extensively about the relationship between thoughts, feelings, and behavior, and they practice identifying maladaptive thoughts such as catastrophizing—jumping to worst-case scenarios.

In CBT, one learns to separate faulty thoughts and beliefs from one’s emotional responses and, consequently, one’s unhealthy behaviors. For example, when the thought “everything will turn out horribly” leads to the feeling “I might as well give up now,” you are likely to give up and thus prove to yourself that you were right all along. After weeks or months of successful CBT treatment, a person should learn to recognize when they catastrophize and change the thought from “everything will turn out horribly” to “I can’t predict the future; things may work out and surprise me,” changing the emotional response and thus the behavior.

Learning more about epigenetics and neuroplasticity gives us a reason to strive to be healthier and happier people. One, because they tell us that we can break negative thought patterns that keep us trapped in unhealthy behaviors. And two, because our actions impact our children—both before we decide to have them and after we bring them into the world.

If you struggle with negative thoughts and related behaviors, contact a therapist.

References:

1. Begley, S. (2011, September 12). Parents’ depression and stress leaves lasting mark on children’s DNA. Daily Beast. Retrieved from https://www.thedailybeast.com/parents-depression-and-stress-leaves-lasting-mark-on-childrens-dna
2. Essex, M. J., Boyce, W. T., Hertzman, C., Lam, L. L., Armstrong, J. M., Neumann, S. M. A., & Kobor, M. S. (2011, September 2). Epigenetic vestiges of early developmental adversity: Childhood stress exposure and DNA methylation in adolescence. Child Development. Retrieved from https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1467-8624.2011.01641.x
3. Kays, J. L., Hurley, R. A., & Taber, K. H. (2012, April 1). The dynamic brain: Neuroplasticity and mental health. Neuropsychiatry and Clinical Neurosciences, 24(2). Retrieved from https://neuro.psychiatryonline.org/doi/full/10.1176/appi.neuropsych.12050109
4. MÃ¥nsson, K. N. T., Salami, A., Frick, A., Carlbring, P., Andersson, G., Furmark, T., & Boraxbekk, C.-J. (2016). Neuroplasticity in response to cognitive behavior therapy for social anxiety disorder. Translational Psychiatry, 6(2). Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4872422
5. Weaver, I. C., Cervoni, N., Champagne, F. A., D’Alessio, A. C., Sharma, S., Seckl, J. R., … & Meaney, M. J. (2004). Epigenetic programming by maternal behavior. Nature Neuroscience, 7(8). Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/15220929
6. Weinhold, B. (2006). Epigenetics: The science of change. Environmental Health Perspectives, 114(3). Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1392256
7. Zimmer, C. (2015, December 3). Fathers may pass down more than just genes, study suggests. The New York Times. Retrieved from https://www.nytimes.com/2015/12/08/science/parents-may-pass-down-more-than-just-genes-study-suggests.html