Genetics and Children's Mental Health—Depression & Anxiety in the Family

Genetics and Children’s Mental Health: Depression & Anxiety in the Family

Opinion by EHN Guest Writer

Written by Andrew, guest writer at EHN, film buff, and crossword enthusiast.

“Why were you crying?” I asked my mom.

It was last October, after my grandmother’s (her mother’s) funeral. The answer should have been obvious, but, as with all families, it was much more complicated than that.

My grandmother struggled with mental health disorders her whole life: a combination of depression, anxiety, and, later in life, dementia. She had the misfortune of growing up in an era—the 1940s and 50s—when there was little understanding of mental health disorders. They were rarely mentioned and even more rarely treated properly.

For my mom and her eight siblings, this meant being raised by a mother who was prone to mental and physical abuse, emotional outbursts, and both suicide threats and actual attempts. Not exactly the Leave It To Beaver fantasy.

Over the decades, it took a toll on their relationships with my grandmother. My grandmother’s mental health disorders likely affected her children’s mental health. Her divorce from my grandfather in the 1970s was followed by a decades-long descent into sadness, isolation, and seemingly irrational behaviour. Her final years were especially hard on my mom, who tended to every tearful phone call, unreasonable request, and belligerent argument.

A Christmas tradition was for my mom, aunts, and uncles—after plenty of eggnog—to tell stories about their childhoods. They would laugh while telling me and my cousins about the violence, the insults, and the threats, but it wasn’t hard to tell that their laughter was hiding their trauma.

It also wasn’t hard to see similar traits across my extended family: case after case of depression or anxiety, each of us treated with our own unique combination of pharmaceuticals. I thought that my grandmother’s death, after a lengthy illness, would be met with a sigh of relief from my mom—relief that it was over. After all, it was something that she admitted she had wished for many times. Instead, I was surprised by the tears that followed my grandmother’s passing.

Which brings us back to my question, “why were you crying?” Her answer: “regret.” Regret about how my grandmother’s life had turned out. Regret over the realization that most of it wasn’t my grandmother’s fault. And regret over some of the similarities my mother saw in my upbringing and her own.

Are depression and anxiety unavoidable genetic conditions? Are genetics the only connection between a parent’s mental health and their children’s mental health? Or are there other factors at play? Let’s look at some evidence.

It Runs in the Family

At the age of the 30, I felt lucky to have avoided both the need for glasses (unlike everyone else in my immediate family) and any trace of depression or anxiety. That is until one day at work when I had what felt like a heart attack. After calling my mom, she told me that it was likely an anxiety attack, something my doctor confirmed shortly after.

A few years of trying to manage these frequent attacks on my own wasn’t working out, and I finally gave in to taking lorazepam on an as-needed basis. Had I simply been unable to avoid the inevitable? Is there evidence to support the idea that mental health disorders, indeed, run in the family? Studies do seem to support this hypothesis.

Anxiety, as a disorder, manifests itself as excessive, uncontrollable worry about any number of issues, where the intensity of the worrying is much greater than the true seriousness of the problem. It is described by the clinical diagnosis known as generalized anxiety disorder (GAD).

A recent literature review on the topic of genetics and generalized anxiety disorder discusses the results of research on the heritability of mental illness. Basically, to what degree do a parent’s genetics influence their children’s mental health? One population-based family study found a high incidence of generalized anxiety disorder (GAD) symptoms in children whose parents had GAD—with genetic heritability of 31.6%.[1] And these results aren’t just seen in cases of anxiety. A recent literature review on the topic of genetics and depression reported the following results in studies of twins. In this case, a meta-analysis found a heritability rate of 37% for depression.[2]

But there also seems to be a sliding scale of heritability: the more severe a parent’s mental illness, the more likely their children are to inherit it. A third literature review on the topic of genetics and mental illness reported that that less common yet more complex disorders including autism, schizophrenia, and bipolar disorder, were far more likely to be passed on genetically. And more common, less severe disorders, including anxiety and major depressive disorder, were less likely to be inherited.[3]

I Get It From My Grandmother

Sometimes, we look at our families and see traits that we would love to inherit: skills in the kitchen, athletic abilities, or a great singing voice. And sometimes we see things that we don’t want. Addictions (which I previously wrote about here), violent behaviour, or, less seriously, a penchant for dad jokes. But sometimes looking at just your parents isn’t enough—you have to look further back in your family history.

A multi-generational research study found a compounding effect when it comes to mental illness, especially anxiety. Of participants who had at least two generations of depression in their family before them (i.e. in their parents and grandparents), 59% experienced a mental health disorder. However, when participants had a depressed grandparent, but not a depressed parent, they were less likely to experience depression or any disorder themselves, compared to those with both a depressed parent and grandparent.[4]

Today, you can take a DNA test to trace your ancestors back for hundreds of years, finding out if you’re 23% Dutch or 17% Chinese. If only the same were true for our mental health. Evidence suggests that having more than one generation of depression in your family history makes it more likely that you will experience depression as well. The same multi-generational research study also found that having a grandparent who experiences severe depression makes it more likely that their grandchildren will also experience depression. On the other hand, the study found no effect of having a parent with depression when a person’s grandparents did not have depression.[5] Unfortunately, my cousins and I fall into the former category.

The Family That Stresses Together

Now, all this is not to say that inheriting genetics is the only way our families can impact our mental health. That would be too easy. Whether we like it or not (or inherit it or not), family life can be stressful—sibling rivalry, money problems, divorce, domestic violence. These sources of stress can affect our mental health, particularly depression, later in life. This is especially true if we experience stress at a very young age. While one might think that stress early in life will help prepare a child for adversity later in life, the evidence suggests that stressful events in childhood can negatively affect children’s mental health and increase the risk for depression later on.[6]

Is It Possible to Curb the Effects of Parents’ Mental Health on Their Children’s Mental Health?

As I talked to my mother after the funeral, herself emotionally scarred from the years of battling my grandmother, the self-interested part of me thought about my own future. Would I encounter the same struggles with my mother as she aged? And would my own issues become more severe as the years went on? Is it a foregone conclusion that grandparents’ and parents’ mental health disorders will negatively affect their children’s mental health?

Maybe not. The answer may lie in our brains’ ability to adapt to our environment and circumstances.

A mother who suffers from long-term depression can pass it along to her child through both her genetics and her behaviour. However, if her depression is treated, whether with antidepressant medications or with psychotherapy, she may be able to provide a more nurturing and low-stress environment for her developing child. There is evidence that, through adaptations in the brain, genetic predispositions for depression or anxiety can be overcome. Children with genetic predispositions are less likely to experience depression or anxiety as adults if they have a positive, nurturing relationship with their mothers, especially during their critical developmental phase between two and five years old.[7]

While I am well over the age of five, there is some solace in knowing that future generations have a fighting chance against hereditary mental illness.

EHN Canada’s Mood and Anxiety Program Can Help You

To learn more about EHN Canada’s Mood and Anxiety Program that treats anxiety, depression, and bipolar disorder, or to enrol, please call us at 1-800-387-6198.

References

[1] Dialogues in clinical neuroscience (2017 June 19). Genetics of generalized anxiety disorder and related traits. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5573560/

[2] Frontiers in Psychiatry (2018 July 23). Genetics Factors in Major Depression Disease. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6065213/

[3] World Psychiatry (2017 May 12). Etiology in psychiatry: embracing the reality of poly‐gene‐environmental causation of mental illness. Retrieved from https://onlinelibrary.wiley.com/doi/full/10.1002/wps.20436

[4] PubMed (2005 Jan). Families at high and low risk for depression: a 3-generation study. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/15630070

[5] PubMed (2005 Jan). Families at high and low risk for depression: a 3-generation study. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/15630070

[6] Frontiers in Psychiatry (2018 July 23). Genetics Factors in Major Depression Disease. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6065213/

[7] Journal of Psychiatry and Neuroscience (Jan 2017). The adaptive brain in mental health: overcoming inherited risk factors. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5373710/

 

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