Childhood Abuse, Complex Trauma and Epigenetics
Epigenetics refers to the study of a natural phenomenon and to the phenomenon itself. Epigenetics is the study of the mechanisms that turn on and off the expression of our genes without altering the DNA sequence. Epigenetics is also used to refer to the changes in expression of our genes.
Factors such as age, nutritional habits, psychological stress, physical activity, working habits and substance abuse can trigger changes in gene expression (Alegría-Torres, 2011). These changes in gene expression, epigenetics, happen all the time in the natural world.
For example, two identical twins, born with the exact same DNA sequence may not express the same genes. One may develop an illness while the other does not. Even diseases that are highly heritable are not guaranteed to develop in both identical twins. If your identical twin has schizophrenia, you have a 53% chance of developing schizophrenia (Roth, Lubin, Sodhi, & Kleinman, 2009). But If you have the exact same DNA, and schizophrenia is genetically heritable, why do you not have 100% chance of developing the same disorder?
Our environment and lifestyle impacts our gene expression.
For better or for worse, the DNA we are born with does not predetermine our health. Life experiences and environmental factors play an important role in who we become.
For people facing mental health challenges, and for therapists providing treatment, understanding that DNA is not destiny can help shape treatment.
Epigenetics and inherited trauma; an experimental manipulation
In a recent study, researchers showed how interpersonal early life stress can impact second and third generation offspring. Researchers exposed mice offspring to early and unpredictable separation from their mother from day 1 to 14. The mother was subjected to stress and the offspring were physically restrained or placed in cold water. This kind of situation is classified as chronic and unpredictable stress.
The offspring displayed depressive symptoms, as was expected. However, the interesting result of this study was what occurred with the second and third generation offspring. The next generations were raised normally. However, the later generations also displayed abnormally high rates of depressive symptoms.