“He looks just like his dad.” I actually said that very thing this morning when I was looking at a graduation party invitation that we received from some family friends. It’s funny when we spot things in a kid’s behavior or appearance that reminds us of their parents. It’s also funny how the phrase “(S)he is just like you” can be a compliment or an accusation. Considering that we get half of our DNA from each biological parent, it makes a lot of sense that we would be similar to them in many different ways. We inherit physical traits from them, as well as emotional traits. We can also inherit physical and mental illnesses as well, and this can definitely bring about some challenges. Today I wanted to write about the influence of genetics on our mental health.
Let me start by reassuring everyone that I’m not being a doom-sayer here. You may be especially like your parents in some ways, but you are your own, unique person. There are chances that you may inherit their strengths or their challenges, but no trait is guaranteed to be passed down. This means that living in fear of a problem manifesting is a surefire way to rob you of the joys of today while worrying about something that may not happen tomorrow.
Some mental health conditions* such as Depression, Anxiety, Obsessive Compulsive Disorder, and even Post Traumatic Stress Disorder are inherited at widely varying rates between 20-40%. Alcohol use disorders and Anorexia have higher rates at 50-60%. Higher still are inherited rates of Bipolar Disorder, Autism Spectrum Disorder, Schizophrenia, and Attention Deficit Hyperactivity Disorder at around 75%.
Maybe you read the first sentence of that paragraph and thought, “There’s no way that PTSD can be passed down. It is a reaction to trauma.” However, our reactions to trauma are incredibly complex and personal. Two people could be exposed to the same traumatic event, but they may not both have adverse responses to it. It has a lot to do with the way that the event was processed in their minds, along with personal protective factors that the individual carries with them before the event happened. Someone might be more vulnerable to a traumatic event based on their genetics. To muddy the waters even further, a parent’s traumatic experiences can actually alter the way their genetics are expressed, and that can be passed on to their children. This has to do with something called epigenetics.
In 1990, the human genome project began with a goal of mapping out human genes. When the first draft of the human genome was completed, the president held a press conference, and the expectation was that we were going to figure out which genes held which traits. Unfortunately, they found that it isn’t that simple. In reality, our traits are expressed through a combination of different genes and how they interact with each other. Across our genome, there may be thousands of risk variants that result (or don’t result) in a psychiatric condition*. Epigenetics** refers to how we all have different possibilities of traits that can be expressed by our genes, and the expression of these different traits can be turned on and off as we go through our lives by our environments and experiences.
All of this isn’t to say that anyone should panic if their family includes a history of mental health disorders. Knowledge is power, and when one knows that they are at an increased risk of developing a mental health problem they can take steps to protect themselves. If a family has a long history of alcohol or substance use problems, great care should be taken to explain to kids as they grow up that they should be especially careful about drinking or drug use. Families with a history of depression or anxiety should encourage safe expression of feelings in their children. They should also introduce protective factors, like involvement in clubs or groups, ensure developmentally appropriate sleep schedules, provide healthy food, and encourage frequent exercise. Making sure that pediatricians are aware of family risks can help them to monitor kids. When these kids turn into adults, knowing of increased risks can help them develop protective factors and even arrange mental health care for themselves when needed.
The different possible combinations of human DNA are unfathomably large, which means that there has never been anyone exactly like you on this planet, nor will there ever be again. You are truly one of a kind, even if you are similar in some ways to your family members. Even when there is risk of certain traits, we have to remember that we can’t read the parts of our story that aren’t written yet.
*https://www.psychologytoday.com/us/blog/evolutionary-psychiatry/201909/genetics-and-mental-illness
**https://www.cdc.gov/genomics/disease/epigenetics.htm