Zach Lucero

The Epigenetics of parenting: Molecular biology of stress, mental health, resilience, and intergenerational trauma

The gender reveal party is over. The baby shower has left the mother-to-be with baby clothing, diapers, and books on how to be a good parent. All that is left is to wait for the baby to arrive. This is a time of reflection about how to be the best parent possible to the new life about to be born.

Parents contemplate their own upbringings and how they will be different for their children. Being a good parent is important to creating happy, healthy adults who are successful in their lives. It seems the success and failure of their children rests primarily on their ability to get this difficult job right.

Parenting styles and beliefs

Kelly Sikkema

In the past, parents (particularly mothers) have been blamed by the medical community for their children’s illnesses and failures. Between 1940 and 1970, schizophrenia was blamed on bad parenting and bad mothering, in particular. Close relationships between a mother and her child were suspected to be the cause of emotional dependency in adulthood. A focus on the emotional health of the mother in relation to the development of her child has predominated the history of medicine and continues to this day. Parents are taught to believe that their influence on children is the primary source of their well-being, and certainly there is some truth to that.

It is not enough anymore to be a “good enough” parent. There is pressure on parents to be perfect. The question, of course, is how to achieve this. During pregnancy, most parents focus on the development of the fetus and the birthing process itself. There are resources available to help guide parents through the prenatal and birthing processes. After the baby arrives into the world, things become less transparent.

Advice on how to be the best parent is diverse and at times conflicting. From attachment parenting to sleep training, potty training, or discipline, any number of sources provide different advice for apprehensive parents to take.

A parent’s style of parenting is also under scrutiny.  Authoritarian parents are thought to raise children who are hostile or aggressive, while children raised by authoritative parents are believed to be happy and successful. Parents with a permissive style are in danger of raising children with a higher risk of health problems. The public scrutiny can be agonizing, and many parents exhaust themselves trying to make the best choices on how to raise their children.

Old medical literature and prevailing social beliefs paint parents as the primary drivers of happiness and success in their children’s lives. But what about the influence of peers on social-emotional development? A study conducted by the University of Pennsylvania suggested that peer relationships play a powerful role in the development of a child’s social emotional skills. This influence begins in early childhood when many children are in daycare and continues through the important years of adolescence. Good parenting and peer relationships, it seems, are important, but they are not the only drivers of individual outcomes.


Are genes everything?

Braño

According to a long-term study done by the University of Minnesota, the genetic makeup of a child contributes more significantly to personality than parenting. Personality traits were measured in sets of identical or fraternal twins that were either raised together or apart. Among the participants, twins raised apart displayed remarkable similarities.

Traits found to be genetically inherited included leadership, traditionalism, a sense of well-being, vulnerability to stress, ambition, and the need for personal intimacy. The genetic inheritance of these traits is complex, and cannot be defined by one particular gene. This research at first seems to refute the social science dogma that good parents make good children, and reflects a growing conflict in the nature vs nurture debate on the role of biology in the health and well-being of children.

Inheritance of genetic material from the parents can regulate the expression of genes and determine the phenotype, or observable traits, in an individual. For example, traits like eye or hair color are passed on to children through inheritance of DNA, which is the blueprint that provides the instructions for the expression of many traits and behaviors. It is often suggested that a child’s behaviors and mental health concerns may be due to both environmental and genetic factors.


We are more than what we’re born with

New research in the field of epigenetics raises questions about how a child’s genes are expressed. The field of epigenetics studies how a person’s experiences alter how DNA is expressed, which can ultimately impact human behavior and disease. These changes are caused by the addition to or removal of a chemical group to DNA and its associated proteins, which has the effect of turning genes on and off. These epigenetic changes are thought to be due to factors like stress, environmental influences, and lifestyle choices.

In the context of parenting, a child can inherit DNA from each of its parents, but environmental factors can impact the genetic traits that are expressed. This has the potential to affect a child’s response to stress, adversity, fear and their capacity for resiliency.

Epigenetic changes to DNA can also be impacted by parent-child interactions. In studies in mice, maternal separation led to an increase in stress hormones. These changes increased the physical and emotional response of the offspring to stress.


Childhood adversity, bullying, and resilience and fear

Zika Radosavljevic

Exposure to abuse in early childhood contributes to chemical modifications of DNA leading to a reduced ability of the brain to adjust in response to experiences. Post-mortem studies of the area of the brain involved in learning, memory, and emotions also show modifications to DNA that can lead to depression and an increased stress response in individuals who have experienced abuse.

Children who are bullied by their peers also show a distinct pattern of modification to their serotonin transporter genes. Serotonin is a hormone believed to play a role in happiness and well-being. The epigenetic effects of bullying are associated with depression, anti-social behavior, and unresolved trauma.

It has been documented that childhood adversity and trauma decrease a person’s ability to manage stress, and increase their vulnerability to substance abuse mental health disorders. Childhood stress has also been linked to a vulnerability to mental health disorders and substance abuse. Each interaction and experience that the child has poses the potential to alter gene expression leading to difficulties with resilience or managing fearful responses. In addition, intergenerational trauma has the potential to introduce epigenetic changes.

Resilience is defined as the ability to adapt to stressful situations in a healthy way. It is not surprising that epigenetics plays a role in this adaptability. High maternal care has been shown to induce epigenetic alterations that decreased the stress response in offspring. This implies that infants who receive poor maternal care experience a heightened stress response when exposed to stressful situations. This heightened stress response may involve fear or anxiety.

The fear response is related to memory consolidation in the hippocampus and activity in the amygdala, the area of the brain involved in the experiencing of emotions. The conversion of short-term, fearful memories into durable long-term memories is mediated by chemical modifications to histones and DNA. Fear can become excessive and persistent, leading to anxiety disorders and post-traumatic stress disorder. Memory extinction is possible using exposure therapies which are also thought to be induced by histone and DNA modifications. Epigenetics, it seems, may partially be responsible for the development of anxiety disorders and maladaptive responses to trauma. It also appears possible to reverse these negative effects.

The science does not stop there. Researchers have suggested that a child’s development is not only impacted by its environment and parenting, but by parental traumas that occurred before the child was born.


The trauma didn’t start with you

Studies have shown that children of Holocaust survivors displayed an increased stress response. Chemical changes were seen in the DNA of Holocaust offspring, suggesting an epigenetic explanation for the offspring’s own post-traumatic stress disorder symptoms. It has also been suggested that parental exposure to early stress and trauma may induce epigenetic changes in germ cells (egg and sperm) leading to altered gene expression in the offspring.

If past experiences can affect offspring, what role do prenatal events play? The study of fetal interactions in the womb has found that prenatal stress affects the development of biological systems which mediate the stress response. Changes in gene expression are related to chemical DNA modification and the age of the fetus, with more severity seen at earlier times in the period between conception and birth. Maternal depression during the pre- and postnatal period increases a child’s stress response and puts them at risk for mental health problems. If the mother is depressed while the child is in the womb, the child has a greater likelihood to be depressed as well.

Reversing epigenetic changes is still a new area of psychological research. Studies have shown that the process of desensitization, a form of exposure therapy that decreases the negative response to traumatic memories, may turn back fear-driven epigenetic changes. Some studies suggest that the therapeutic process, regardless of therapeutic orientation, may induce social learning and act as markers for psychopathology and predictors of therapeutic response. Therapeutic change experienced by the parents may even produce epigenetic changes that can be passed down to offspring.


Tying it all together

The research suggests that parents must provide a healthy, supportive environment and avoid exposing their children to considerable stress. Environmental enrichment has been shown to improve learning and memory. A stimulating physical and social environment coupled with low stress conditions can reduce or eliminate behavioral symptoms in traumatized adults and their offspring. Nurturing physical behavior also impacts the chemical modification of DNA and leads to reduced anxiety and increased overall well-being – something that may persist for years. The importance of hugging cannot be emphasized enough.

Parenting is without a doubt, one of life’s greatest challenges. As parents, we try to meet our children’s needs and nurture their growth and development. The science of epigenetics brings the role of parenting into a different focus. Although most parents try their best to be good parents, the role of trauma, stress and environment in altering gene expression in offspring has chilling implications. In short, DNA provides the blueprint to the child’s development, but epigenetics influence how that blueprint is ultimately expressed. The parents who take an active role in healing from their past traumas will give their offspring the best chance to thrive.

1 thought on “The Epigenetics of parenting: Molecular biology of stress, mental health, resilience, and intergenerational trauma”

  1. Dear Kristen Math, thank you for this cogent exploration of parenting within the complexities of nature, nurture and epigenetic pivots. It’s never too late to have a good childhood. Trusting us and ours to hope, health, happiness and harmony.

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