Medically reviewed by Jill Johnson, DNP, APRN, FNP-BC
Written by Our Editorial Team
Last updated 12/26/2021
If you’ve ever watched a parent or sibling deal with depression, you’ll know how debilitating and serious it can be.
Depression is a common type of mental illness. In fact, according to data from the 2019 National Survey on Drug Use and Health (NSDUH), an estimated 7.8 percent of all American adults dealt with at least one major depressive episode during the previous year.
Research suggests that depression is at least partly heritable, or caused by genes. However, if one of your close family members currently suffers from depression or has previously developed a form of depressive illness, this doesn’t mean that you’ll also become depressed.
Below, we’ve dug into the research to determine how much of depression is caused by genetic factors and how much is environmental.
We’ve also discussed what you need to know if you have one or more family members affected by depression and have concerns about your potential risk.
Although we all like to think that we’re totally in control of the way we think, feel and behave, the reality is that our genes have at least some influence on these elements of our lives.
Within the scientific community, and particularly within psychology, there’s a long-running debate about the effects of nature versus nurture, or the effects of a person’s genes versus the effect of environmental factors, such as a person’s home environment or relationships.
When it comes to depressive disorders such as major depression, research suggests that a mix of both environmental and genetic factors are involved.
For example, known risk factors for depression include sudden changes in your life, trauma and stress.
Depression can also develop as a result of illnesses such as diabetes or cancer, or as a side effect of medications used to treat these and other health conditions.
On the genetic side, research shows that people who have close family members at an elevated risk of depression also face a higher risk.
For example, twins face a different depression risk based on the percentage of their genes that are shared with their siblings.
Identical, or monozygotic twins, who share all of the same genes, are more likely to have a high shared risk of depression than fraternal, or dizygotic, twins, who share half of their genes.
Findings from adoption and family studies also suggest that the risk of developing depression is at least partly heritable.
So, how much of a factor are genes in depression? Researchers haven’t figured out any precise numbers just yet, but most believe that a person’s family history has a significant impact on their risk of developing depression.
According to the Stanford University School of Medicine, if a person has a parent or sibling affected by major depression, their risk of experiencing depression at some point in life is probably two to three times higher than that of a typical person, or approximately 20 to 30 percent.
Recurrent depression, or repeated depressive episodes, appear to be even more closely linked to a person’s family history.
This type of depression is much less common than major depression. However, if a person has a parent or sibling who experienced recurrent depression in childhood or early adulthood, their own risk of developing this form of depression is approximately 12 to 25 percent.
Interestingly, some researchers have found specific loci (a position within a chromosome where a single gene or genetic marker is found) that may play a role in depression.
In a study published in the American Journal of Psychiatry in 2011, a team of researchers used genetic data from more than 800 families to identify genes that may contribute to depression.
They found that chromosome 3p25-26 appears to possibly be linked with severe recurrent depression.
While this may not be a “depression gene,” the finding is an interesting one that may help to shed light on the numerous factors that can cause or contribute to depression.
Other research has dug even deeper into the potential genetic origins of depression. In a large genome-wide association study involving records from more than one million people, a team of researchers identified 178 risk loci linked to depression.
Speaking to the media on the findings of the study, one of the researchers noted that there may be thousands more genetic variants involved in the development of depression.
Put simply, the genetics of depression and other mental disorders are complicated, far more so than the popular idea of a “depression gene” might make things seem.
Depression isn’t the only mental health disorder with a genetic component. Researchers have spent decades exploring the link between genes and mental health, with studies showing that many common mental illnesses appear to be caused, at least in part, by genetic factors.
For example, a review published in the journal Current Opinion in Psychiatry in 2016 noted that several anxiety disorders, including generalized anxiety disorder (GAD), social anxiety disorder (SAD) and panic disorder appear to be linked to genetic markers.
Other research has found that certain phobias — anxiety disorders defined by fears of situations or objects — may have a genetic component.
Findings from twin studies also suggest that the heritability of bipolar disorder is between 60 and 80 percent.
If you have one or several close family members with depression, it’s easy to think that based on their experience, you too will eventually develop depression at some point in life.
This isn’t necessarily true. While depression is clearly at least partly hereditary, having a parent or sibling with depression only means that you have a higher risk of developing depression than the average person, not that you’re guaranteed to become depressed.
A large range of factors appears to play a role in depression, including your genes, environment and other aspects of your mental health.
Your family’s mental health history is just one of these factors. It doesn’t define you, nor does it override the many other important things that can affect your mental health and wellbeing as an individual.
If you think you have major depressive disorder, it’s important to talk to a licensed mental health provider.
You can do this by asking your primary care provider for a mental health referral, or by talking to a licensed psychiatry provider from home using our online psychiatry service.
Depression is treatable with medication, therapy and changes to your habits and lifestyle. If you have depression, your mental health provider may recommend a combination of approaches to treat your symptoms and help you recover.
Depression is treated using medications called antidepressants. These work by increasing the levels of chemicals in your brain responsible for regulating your feelings and moods.
Your mental health provider may prescribe a selective serotonin reuptake inhibitor (SSRI) to treat your depression.
In some cases, you may be prescribed another type of antidepressant, such as a tricyclic antidepressant or serotonin-norepinephrine reuptake inhibitor (SNRI).
Antidepressants can take several weeks to start working, and they often improve symptoms of depression such as poor sleep and concentration before they improve your mood.
Our full list of antidepressants discusses how antidepressants work and lists the most common medications used to treat depression.
Like other psychiatric disorders, depression often improves with psychotherapy. In fact, research has found that a combination of psychotherapy and antidepressants is more effective at treating depression than medication alone.
Common forms of therapy used to treat clinical depression include cognitive-behavioral therapy (CBT), problem-solving therapy and interpersonal therapy (IPT).
Our guide to therapy for depression goes into more detail about how psychotherapy works as a treatment for depression, as well as what you can expect during a therapy session.
Small, simple changes to your lifestyle can often make your depression symptoms less severe and improve your results from medication and therapy.
Try the following habits and lifestyle changes to ease your depression symptoms:
Keep yourself physically active by exercising several times a week.
Spend time around your friends and family members to prevent yourself from becoming socially isolated.
Write down a list of goals for yourself and focus on making steady, realistic progress to accomplish them.
Set aside five to 15 minutes a day to practice mindfulness meditation, which may help to improve the effects of your depression treatments.
Avoid making any major life decisions, such as changing careers or making changes to your relationships, until you feel better.
Our list of ways to help depression goes into more detail about how small changes to your daily life can have a big impact on the way you think, feel and behave.
Depression is at least partly hereditary, with research showing that people with family members who’ve been depressed have a higher risk of becoming depressed themselves.
This means that if you have a parent or sibling with depression, or who has faced depression in the past, it’s important to be aware of your own personal risk.
Depressive symptoms can vary from person to person. Our guide to the most common signs of clinical depression explains what to look out for if you’re concerned that you may be depressed, as well as how you can seek expert help.
If you’re feeling depressed and want to seek expert help, you can connect with a mental health professional from home using our online mental health services.
You can also learn more about dealing with depression, anxiety and other mental illnesses with our free online mental health resources and content.