The Epigenetics of Childhood Trauma

By Diane McIntosh MD, FRCPC: For More Info, Go Here…

Part 1: How childhood adversity can provoke long-term health consequences.

This is the first of two posts regarding the epigenetics of childhood adversity, based on excerpts from my new book, This Is Depression.

Epigenetics is the science of gene expression. Your DNA is written in permanent marker; it can’t be changed or erased. Epigenetics is written in pencil: How our genes are expressed can change, thus we change our tune throughout our life. Epigenetics is the interface between nature (the genes you inherited from your parents) and nurture (your life experiences). How your genes are expressed, whether they are turned off or on, or played softly or harshly, depends on the type of genes you inherited from your parents, your developmental stage (e.g., pubertymenopause), and your environment.

We now know that our inherited genetic code, as well as life events and our environment, can affect how our genes are expressed. Toxin-related epigenetic changes are an example of our environment impacting gene expression. The scary part of this story is that research has demonstrated that epigenetic changes related to toxins can be inherited by our children.

Research on schizophrenia provides several examples of gene-environment interactions that may trigger the development of the illness. Examples of potential triggers that can alter gene expression and might provoke the development of schizophrenia include infections during pregnancy, abnormal bowel flora (microorganisms that live in the gut), and smoking cannabis.

These and other environmental exposures are of greatest concern in vulnerable individuals, like those who have a family history of the disorder. Some families have specific genes in their DNA that likely constitute a risk for the disorder, and with exposure to a specific infection or cannabis, a gene that promotes schizophrenia might be activated, resulting in the onset of symptoms.

In my next post, I’ll share how childhood adversity can provoke epigenetic changes that may impact physical and mental health.

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