Challenging the inevitability of inherited mental illness

By Lindsey Phillips

With a family history that famously includes depression, addiction, eating disorders and seven suicides — including her grandfather Ernest Hemingway and her sister Margaux — actress and writer Mariel Hemingway doesn’t try to deny that mental health issues run in her family. She repeatedly shares her family history to advocate for mental health and to help others affected by mental illness feel less alone.

And, of course, they aren’t alone. Mental health issues are prevalent in many families, making it natural for some individuals to wonder or worry about the inherited risks of developing mental health problems. Take the common mental health issue of depression, for example. The Stanford University School of Medicine estimates that about 10% of people in the United States will experience major depression at some point during their lifetime. People with a family history of depression have a two to three times greater risk of developing depression than does the average person, however.

2014 meta-analysis of 33 studies (all published by December 2012) examined the familial health risk of severe mental illness. The results, published in the journal Schizophrenia Bulletin, found that offspring of parents with schizophrenia, bipolar disorder or major depressive disorder had a 1 in 3 chance of developing one of those illnesses by adulthood — more than twice the risk for the control offspring of parents without severe mental illness.

Jennifer Behm, a licensed professional counselor (LPC) at MindSpring Counseling and Consultation in Virginia, finds that clients who are worried about family mental health history often come to counseling already feeling defeated. These clients tend to think there is little or nothing they can do about it because it “runs in the family,” she says.

Theresa Shuck is an LPC at Baeten Counseling and Consultation Team and part of the genetics team at a community hospital in Wisconsin. She says family mental health history can be a touchy subject for many clients because of the stigma and shame associated with it. In her practice, she has noticed that individuals often do not disclose family history out of their own fear. “Then, when a younger generation person develops the illness and the family history comes out, there’s a lot of blame and anger about why the family didn’t tell them, how they would have wanted to know that, and how they could have done something about it,” she notes.

Sarra Everett, an LPC in private practice in Georgia, says she has clients whose families have kept their history of mental illness a secret to protect the family image. “So much of what feeds mental illness and takes it to an extreme is shame. Feeling like there’s something wrong with you or not knowing what is wrong with you, feeling alone and isolated,” Everett says. Talking openly and honestly about family mental health history with a counselor can serve to destigmatize mental health problems and help people stop feeling ashamed about that history, she emphasizes.

Is mental illness hereditary?

Some diseases such as cystic fibrosis and Huntington’s disease are caused by a single defective gene and are thus easily predicted by a genetic test. Mental illness, however, is not so cut and dry. A combination of genetic changes and environmental factors determines if someone will develop a disorder.

In her 2012 VISTAS article “Rogers Revisited: The Genetic Impact of the Counseling Relationship,” Behm notes that research in cellular biology has shown that about 5% of diseases are genetically determined, whereas the remaining 95% are environmentally based.

The history of the so-called “depression gene” perfectly illustrates the complexity of psychiatric genetics. In the 1990s, researchers showed that people with shorter alleles of the 5-HTTLPR (a serotonin transporter gene) had a higher chance of developing depression. However, in 2003, another study found that the effects of this gene were moderated by a gene-by-environment interaction, which means the genotype would result in depression if people were subjected to specific environmental conditions (i.e., stressful life events). More recently, two studies have disproved the statistical evidence for a relation between this genotype and depression and a gene-by-environment interaction with this genotype.

Even so, researchers keeps searching for disorders that are more likely to “run in the family.” A 2013 study by the Cross-Disorder Group of the Psychiatric Genomic Consortium found that five major mental disorders — autism, attention-deficit/hyperactivity disorder (ADHD), bipolar disorder, major depressive disorder and schizophrenia — appear to share some common genetic risk factors.

Read more https://ct.counseling.org/2019/08/challenging-the-inevitability-of-inherited-mental-illness/