Epigenetics And Mental Health: How Environmental Factors Change Gene Expression

You might have heard that a pregnant person’s diet can affect the genetic health of their baby, but did you know that a person’s stress levels while pregnant can have similar effects? Beyond pregnancy, a child’s environment and upbringing can continue to affect their genetics after birth. Adults can also undergo changes to their gene expression due to their unique experiences.

The study of how environmental influences affect genes is called epigenetics. Despite the decades-long research and debate of nature versus nurture, scientists are still learning how much the world can change how genes work. To understand how your environment and experiences can affect your long-term health, reviewing how epigenetics work, conditions resulting from epigenetic changes, and positive ways to use epigenetics may be helpful.

What is epigenetics and its mental health effects?

According to Environmental Health Perspectives, the word “epigenetic” means “in addition to changes in genetic sequence.” In practice, however, epigenetics is the study of how experiences and environmental factors can change how genes work without changing the DNA sequence itself.

Epigenetics changes genetic expression, which can be described as the “instructions” that come with your genes, teaching your body how to read them and what to do with them. It’s often considered an “on/off switch” that controls when and where proteins are created in a cell. These proteins determine the function of each cell that makes up your body.

Because each person’s environment and experiences can alter their genetic expression, there may be changes in how genes are being read, the proteins genes create for cells, and the resulting functionality of each cell in the body, which could lead to changes in biological processes, as well as physical and mental health consequences.

The epigenetic process

Scientists have identified several types of epigenetic change (called epigenetic mechanisms), including the following. 

DNA methylation

DNA methylation is among the most well-known epigenetic mechanisms due to its ability to be studied. It is a natural human process in which methyl groups are added or removed from DNA. However, DNA methylation has been linked to several health disorders as well, such as cancer, and could cause epigenetic silencing.

Histone modification

Histone modifications – including histone methylation, acetylation, phosphorylation, and ubiquitylation – can affect how well genes can be accessed and read, giving them the ability to be turned “off” or “on.”

Chromatin modification

Chromatin is made up of histones and DNA. Modifications can affect how histones and DNA interact, leading to alterations in gene transcription, DNA repair, DNA replication, and the organization of chromosomes.

SUMOylation

Small ubiquitin-related modifier proteins (SUMO) can attach to lysine side chains, modifying and producing branched proteins and changing their shape, stability, and affinity as a result.

Non-coding RNA

Coding RNA creates proteins, while non-coding RNA (ncRNA) controls and regulates gene expression. Changes to ncRNA can affect protein production and could modify histones.

Sources of epigenetic change in gene expression

Epigenetic modifications can be caused by several sources, including the following. 

Age and development

Epigenetic modification isn’t necessarily negative. It can be normal for epigenetics to occur as one ages and develops. In the womb, epigenetics plays a central role in fetal development, designating which cells can perform which job within the body. Additionally, a 2012 study looked at DNA methylation in a newborn, a 23-year-old, and a 103-year-old and discovered that a person’s level of DNA methylation decreases with age.

Childhood experiences and epigenetic changes

Because a young person may undergo higher levels of epigenetic alterations, childhood experiences can significantly shape gene expression. For example, abuse, neglect, or trauma in childhood can lead to mental and physical health conditions later in life, while supportive relationships and learning opportunities can lead to better health overall.

If you or a loved one is experiencing abuse, contact the Domestic Violence Hotline at 1-800-799-SAFE (7233). Support is available 24/7.

Smoking and harmful changes in epigenetics

Cigarette smoking can cause DNA methylation and histone modification that increases one’s risk of cancer, cardiovascular disease, and COPD, as well as ADHD.

Alcohol

Chronic alcohol consumption can contribute to DNA hypomethylation and DNA and histone methylation and impacts ncRNAs, all of which can increase one’s risk of liver disease and tissue damage as well as anxiety and depression.

If you are struggling with substance use, contact the SAMHSA National Helpline at (800) 662-4357 to receive support and resources.

Environmental pollutants can lead to change in gene expression

Chemicals in one’s environment can lead to several epigenetic mechanisms, including DNA methylation, histone modifications, and microRNA (miRNA) expression, increasing the risk of disease and psychiatric disorders.

Diet

Compounds in different foods and how many calories are consumed can play positive and negative roles in epigenetics. For example, the EGCG compound found in green tea may act as a tumor suppressor by modulating epigenetic processes. Nutritional quality has also been shown to improve mental health.

Physical activity

DNA methylation and histone modifications are linked to physical activity, and regular exercise can decrease the risk of developing metabolic or chronic diseases, reduce depression, and improve cognitive function.

Stress

Stress, especially early in life, can cause epigenetic mechanisms such as DNA methylation and histone modification, resulting in mental health conditions such as depression and post-traumatic stress disorder (PTSD).

Work and sleep schedule

Working the night shift for a job can lead to CpG site methylation and differential DNAm patterns, which could result in an increased risk of breast cancer and sleep disorders. 

Can your gene expression be passed on to children?

Changes to gene expression through epigenetics can be passed onto offspring through a process called transgenerational epigenetic inheritance. Studies have shown the effects a parent’s epigenetics can have on their children, including a 2018 study that monitored the sons of Prisoners of War (POWs) during the Civil War. Despite the children being born after the war was over, the sons were between 1.09 and 1.2 times more likely to die than sons of non-POWs, depending on their camp conditions.

Epigenetics effects on mental health

Specific epigenetic mechanisms can negatively impact mental health. Although it may depend on the source, including if it was inherited from a parent, mental health conditions and symptoms caused by epigenetics can include the following. 

Cognitive dysfunction and health outcomes triggered by gene changes

Depression

Depression can be caused by genetics and environmental factors. Negative life experiences, such as trauma or neglect, could create epigenetic modifications that increase one’s risk of developing depression. Similarly, a parent experiencing epigenetic mechanisms resulting in depression could pass the condition to their offspring. 

Anxiety

Genetics and environment can also influence one’s anxiety. Anxiety disorders, such as generalized anxiety disorder (GAD) or obsessive-compulsive disorder (OCD), can either develop due to life experiences and environmental factors or be passed down from a parent. Inherited epigenetics may also play a role in a person’s susceptibility to developing anxiety disorders. 

Schizophrenia

Schizophrenia has been linked to nicotine use and exposure to nicotine, which can change one’s genetic expression through epigenetics. Schizophrenia is also highly heritable, showing strong links between parents and children with this condition.

Parental substance use disorder and health effects in children: Epigenetics and mental health outcomes

Because substance use, such as drugs and alcohol, can lead to epigenetic modifications, substance use disorder can also be passed from parent to child. Additionally, one’s susceptibility to developing substance use disorder can be impacted by their environment and life experiences, especially negative ones.

Positive effects of epigenetics on mental health conditions

Although certain substances and experiences can negatively impact one’s genetic expression, studies have shown that epigenetics can be reversible. Additionally, positive life experiences and environments can positively impact one’s genetic expression.

For example, adopting a healthy diet and regular exercise schedule may begin to reverse the previous effects of a less healthy diet and a more sedentary lifestyle. Additionally, practices such as mindfulness, meditation, and cognitive-behavioral therapy may reverse and heal the mental health impacts of negative environments and life experiences.

Support options for epigenetics and mental health

If you’ve lived through negative life experiences or in adverse environments, one way to begin making a positive change to your genetic expression and your mental health is through cognitive-behavioral therapy. Research has shown that cognitive-behavioral therapy can change epigenetic states, often improving mental health as a result.

Depending on the physical and mental health conditions you might be experiencing, it may not be easy to seek in-person treatment. In those cases, online therapy through a platform like BetterHelp can be a helpful and impactful alternative. With online therapy, you can receive care from a licensed mental health professional from the comfort of your home without taking additional health risks by traveling to appointments. In addition, you may access unique resources like group sessions and worksheets. 

Online therapy help for epigenetics and mental health outcomes

Research has found online therapy as effective as in-person treatment. In a 2017 review, researchers found internet-based cognitive-behavioral therapy to be effective in “the treatment and management of various psychiatric disorders like depression, GAD, social anxiety, panic disorders, phobias, addiction, substance use disorders, adjustment disorder, bipolar disorder, and OCD.”