Is Depression Hereditary?

According to experts at Stanford University, at least 10 percent of people in the U.S. will experience major depression at some point in their lives. Because depression is prevalent, it's important to understand what causes and influences it so we can appropriately identify and treat people suffering from this debilitating condition.


One important influence on an individual's likelihood of developing depression is genetics.

Scientists estimate the percent of cases of an illness due to genes (its heritability) by looking at patterns of illness in families, especially those with twins. They've determined depression is about 40 to 50 percent heritable, perhaps a bit higher for severe depression. Researchers say this could mean the tendency to become depressed is almost completely genetic for some people, and not really genetic at all for others.

In one study, researchers tracked individuals from 12 multi-generational Armenian families exposed to a major earthquake in 1988. They found that 61 percent of the variation in depression was attributable to genetic factors (as was a significant percent for anxiety and Post Traumatic Stress Disorder, or PTSD). The researchers concluded that genetic makeup renders some people more vulnerable to depression, anxiety, and PSTD.

If your parent or sibling has major depression, you have a 20 to 30 percent greater than average risk for depression. This risk climbs to 40 to 50 percent if your family member has recurrent depression or if their depression began early in life.

At the gene level, researchers have identified at least one variation that may cause depression. Two unrelated studies found a strong link between depression and the same genetic variation.

You do not inherit depression from your mother or father. You inherit a combination of genes that can predispose you to depression (or other illnesses). Furthermore, being genetically predisposed does not mean that you will develop depression. Your life experiences influence your biology at least as much as your biology affects your experiences. Factors that may increase the likelihood of developing depression include severe childhood physical or sexual abuse, childhood emotional and physical neglect, severe life stress, and losing a parent at a young age.

Despite a genetic predisposition, you have more control over whether you develop depression than you might imagine. According to an article in Psychology Today, when people educate themselves and take proactive and deliberate steps to get help, the probability of overcoming depression is high. If you are at greater risk, you can learn strategies to help you manage your mood.

Sources: "Genetic Link To Depression." Web. 16 July 2011.

Levinson, Douglas F.,M.D., and Nichols, Walter E., M.D., "Major Depression and Genetics." Stanford School of Medicine. Web.

Yapko, Michael. "What Causes Depression?" Web. 25 May 2007.

Cassels, Caroline. "Susceptibility to PTSD, Anxiety, Depression Hereditary." Medscape Medical News. Web. 22 December 2008.

National Institute of Mental Health. "What Causes Depression?" Web. July 27, 2011.

Lemogne, Cedric, Gorwood, Philip, Boni, Claudette, Pessiglione, Mathias, Lehericy, Stephanie, and Fossati, Philippe. "Cognitive Appraisal and Life Stress Moderate the Effects of the 5-HTTLPR Polymorphism on Amygdala Reactivity." Human Brain Mapping (2011): 1 - 12