Does Depression Run in Families?

Is depression inheritable? From a strictly statistical viewpoint, the answer is yes. A variety of research shows that the children of depressed parents are more likely to be depressed themselves at some point in their lives.

What is less understood is the cause of that link. Is it nature -- a genetic trait that is passed from parent to child? Or is it nurture -- that growing up with depressed parents teaches children how to be depressed? Most experts believe it is a combination of the two.

First, the statistics. One overview of multiple studies suggests a two- to three-times increase in lifetime risk of developing major depressive disorder among first-degree relatives (parents, siblings and children).

[See: 10 Concerns Parents Have About Their Kids' Health.]

But genetic makeup plays only a partial role. Studies of identical twins, for instance, show that when one twin develops depression, the other doesn't in about 30 percent of cases. That is because "there is not a gene for depression," says Michael D. Yapko, a clinical psychologist who has written extensively and lectures worldwide on depression. "There is a genetic vulnerability toward depression, but not a gene. That's where epigenetics become important."

Epigenetics, the study of how and why certain genetic coding becomes expressed as physical or emotional traits, is critical in understanding a disease like depression, Yapko believes. "The risks passed from parent to child aren't primarily in the biology realm. They are in the social realm," he says. More specifically, he points a finger at what he calls "attributional style" -- the way a parent explains or models how the world works. "This is where the hottest research is right now," he says. "When life events happen to us, how we interpret these events determines whether we develop depression. By the time a kid is 5 years old, his attribution style matches mom or dad." So, if mom or dad responds in a depressed or anxious way, the child is more likely to do the same.

A recent study bears this connection out. The study, published in the December 2016 issue of the journal Pediatrics, looked at data from about 22,000 two-parent families who participated in federal health surveys between 2004 and 2008. It found that a child is 70 percent more likely to develop emotional or behavioral problems if the father shows signs of depression. The risk is even higher if mom is depressed. In real numbers, 11 percent of kids are depressed if the father is depressed, 19 percent if the mother is depressed and a remarkable 25 percent if both parents are depressed.

[See: Am I Just Sad -- or Actually Depressed?]

Again, experts believe that genetics play less of a part than the environment the child grows up in. "Environmental stressors such as loss, major life transitions or intensive family or marital conflict can play a role, as can poverty, traumatic experiences and physical illnesses," says psychologist David J. Miklowitz, director of the Child and Adolescent Mood Disorders Program and the Integrative Study Center in Mood Disorders at the UCLA Semel Institute for Neuroscience and Human Behavior in Los Angeles.

What matters is how the child learns to deal with these stressors. Such epigenetic risk factors are transgenerational, Yapko says. "You can't teach what you don't know, and if you cope with stress by getting drunk and passing out, you can't teach your kid how to deal with stress in a healthy way. When mom has postpartum depression and is not emotionally involved, that has a profound impact, and you won't have normal development in the emotional regions of the brain."

Consider a study from 2011, which delved into the associations between depression in fathers of 1-year-old children and the specific parenting behaviors these fathers discussed with their pediatric providers at well-child visits.

Taking interview data from 1,746 fathers, the researchers compiled both "positive parenting behaviors," such as playing games, singing songs and reading stories to their children, and "negative parenting behavior," including spanking. Depressed fathers were much more likely to report spanking their 1-year-old children and less likely to report reading to their kids.

[See: 11 Simple, Proven Ways to Optimize Your Mental Health.]

Critical-thinking skills, Yapko says, make a big difference in whether a child develops depression -- not to mention other psychological or emotional problems. Kids with such skills, Yapko says, have less than half the rates of depression, drug and alcohol abuse, and teenage pregnancy as those who do not learn these skills.

"Is it any surprise that depression rates have increased from 2005 to 2015, given the changes in the world, in technology and how we relate to ourselves?" Yapko says. "While there is a biology component, it is the psychological and social components that are more powerful. Data on epigenetics has made it abundantly clear that environmental influences are leading people to higher levels of depression. It is not so much in biology as in circumstances."

David Levine is a freelance health reporter at U.S. News. He is a contributing writer for athenaInsight.com and Wainscot Health Media, a former health care columnist for Governing magazine and a regular contributor to many other health and wellness publications. He also writes about lifestyle and general interest topics, from history and business to beer and baseball, as a contributing writer for Westchester, Hudson Valley and 914INC magazines. His work has appeared in The New York Times, Sports Illustrated, American Heritage and dozens of other national publications, and he is the author or co-author of six books on sports. You can connect him on LinkedIn.