“I get it from my dad.”
“Depression runs on my mom’s side of the family.”
“My grandpa had depression, so maybe I’m predisposed to it?”
Many people suffering from depression often relay that it “runs in the family.”
Actress Kristen Bell, for example, speaks openly about her battles with depression and says that both her mother and grandmother had the same chemical imbalance.
Is Mental Illness Genetic?
Now science is backing up this claim. A recent study of nearly half-a-million people uncovered 30 genes linked to depression, tripling the number known to play a role in the debilitating disease.
The study, led by the Center for Psychiatric Genomics at the University of North Carolina and published in Nature Genetics, also found 44 genetic variants linked to depression. The meta-analysis reviewed the DNA of more than 135,000 people with depression, and 350,000 people who did not identify as having depression.
“We all carry genetic variants for depression, but those with a higher burden (of related genes) are more susceptible,” said co-author Naomi Wray, a researcher at the University of Queensland in Australia.
The study found that as far as the genetic variants go, everyone carries some of the 44 genetic risk factors linked to depression. The importance of genes rather than environment as the cause of depression differs from individual to individual, but it is almost always some combination of both. Genetics account for about 40 percent of all causes of depression, leaving about 60 percent due to environmental factors, like where and how you live.
“Many life experiences can contribute to the risk of depression, but identifying the genetic factors opens new doors for research into the biological drivers,” added Wray.
Multiple studies for example, including one from the Netherlands in 2009, have found that lifestyle factors including a higher body mass index (or BMI) contributed to patients diagnosed with major depressive disorder (MDD).
Using Your Genes to Help Fight Depression
On the other side of the coin, genes can also play a role in determining how well a person responds to antidepressant medications and what side effects they are most likely to develop.
For example, a patient may be a genetically fast metabolizer of a certain medication, which means that the medication doesn’t stay in the body long enough to effectively treat depression. That same patient may be a slow metabolizer of another medication, which means that the medication stays in the body too long – creating unwanted side effect.
Knowing what kind of metabolizer you are for certain medications all comes down to your unique genetic make-up. That’s where the GeneSight®test comes in; the test can use your genes to determine which medication can work best for you and help your healthcare provider guide your treatment.
At the annual American Psychiatric Association meeting, Assurex Health presented the results of a groundbreaking study,which found a 50 percent improvement in remission and 30 percent improvement in response for GeneSight® Psychotropic versus treatment as usual (TAU). The study included nearly 1,200 patients with moderate-to-very severe depression who had failed at least one antidepressant medication.
While scientists are still researching if depression and other mental illnesses are genetic, the GeneSight test is helping people today.