Inheriting memory

Photo: Contributed - ​Pavel Losevsky

The nature nurture question is more complex and interconnected than it sounds - one fascinating example of this is found in the idea that memory could be inherited. 

Research shows that traumatic experiences can change the DNA in sperm and affect the behaviour of subsequent generations. 

We have long known that traumatic experiences can change the way our brain develops and lead to a higher likelihood of experiencing mental health issues later in life, but it seems these experiences can actually affect the mental health of our children, and even our grandchildren.

Researchers at Emory University in the US studied this question in mice. They trained mice to fear a particular smell and then observed changes in sperm DNA. A section of DNA associated with sensitivity to the particular odour became more active in the sperm and was then passed on to the next generation of mice. The next two generations of mice were then very sensitive to the same smell even without being trained for it. 

It is believed these findings are very relevant to our understanding of phobias, anxiety disorders and PTSD in humans. Some experts believe this trans-generational response will also have implications in other areas of health such as obesity and diabetes. 

These results certainly do seem to further complicate our understanding of the way genetics factor in to mental health conditions such as anxiety disorders. Most psychiatric conditions are known to have at least some genetic component, and are usually more common in relatives. We often think of this as a straightforward passing on of a trait. If I have blonde hair, I am more likely to pass that on to my children.

In recent years, we have learned that our experience of mental health symptoms can change our own genes and brain structure on a physical level. This has been likened to switching genes on or off. 

This is the first indication that the genetic material of our future offspring can also be affected by our experiences. Not only will my own brain change as a result of my anxiety disorder, but the genetic material I pass on may also become more sensitized as a result. 

More research is needed to understand the extent of this effect in humans, but it certainly has the potential to be a game changer in our understanding of the underpinnings of some mental health conditions. 

In the meantime, there are effective treatments available for anxiety and depression. Regardless of the cause of the condition, if you are living with mental health symptoms that are affecting your ability to function or enjoy life, speak with your doctor to learn your options. Help is available.

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.