Key takeaways:
Depression is linked to a combination of factors, including your genetics, your physical health, and your life experiences.
If you have a close family member with depression, it can increase your risk.
If you think you may be depressed, there are many resources and treatments that can help.
Chances are, you know someone with depression. It’s a common mental health condition that can affect your mood, thoughts, and behavior. And, every year, it affects nearly 1 in 10 adults in the U.S.
If you have a close family member with depression, you may have wondered: Could I be at risk for depression too? After all, many health conditions run in families. And when it comes to depression, we know that your genes definitely play a role.
But, in reality, it’s not so simple. Apart from your genetics, there are many other factors that affect your risk — like your physical and mental health, your brain structure, and your life experiences. And even if depression does run in your family, that doesn’t necessarily mean you’ll get it too.
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Let’s take a closer look at what we know about the genetics of depression, as well as other risk factors that matter.
Is depression genetic?
Yes — at least partially.
So far, there’s evidence that many different genes are linked to depression. These genes can be passed down from parents to children, meaning depression can be inherited. In other words, depression can run in the family.
But when it comes to depression, it’s not quite so simple. Though genes are important, they’re not the whole story. Other things matter too.
Here’s what we know so far about depression and genetics.
Heritability
When scientists study genetic disease, they look at something called “heritability.” Heritability tells us how much of a condition is passed down through genes.
Some health conditions have a high heritability. This means they’re mostly caused by genetics. For example, cystic fibrosis is a condition that’s caused by inheriting certain genes from your parents. Its heritability is 100%, which means it’s completely genetic.
Other health problems have a low heritability. The stomach flu, for example, is directly caused by germs — not genes. Its heritability is 0%.
Depression is somewhere in the middle. The heritability of depression is about 40% between first-degree relatives. This means if you have a close family member (like a parent or sibling) with depression, your chances of getting it are higher than someone whose family doesn’t have it. But since it’s only partially hereditary, it’s also possible you’ll never get depression — even if it runs in your family.
Polygenic nature of depression
Depression also seems to be connected to many different genes, not just one or two. Researchers call this a “polygenic” condition (which means “many genes”). Though each gene has a small effect, when they add up it can raise your risk of having depression.
Gene-environment interaction and depression
Your genes can affect your risk of getting depression. But other things matter, too, like your environment and life experiences. Scientists call this a “gene-environment interaction,” which simply means your genes and your life experiences affect each other.
Ongoing genetic research
Researchers are still investigating genetics and depression. New tools like machine learning and artificial intelligence (AI) are making it easier to study huge amounts of genetic data from thousands of people. This can potentially help us find genetic patterns linked to depression.
What are other risk factors for depression?
As we mentioned above, depression isn’t caused by any one single thing. It’s linked to many different factors.
Other risk factors include:
Brain biochemistry: There are chemicals in your brain called neurotransmitters, which regulate many brain functions. Some examples are serotonin, norepinephrine, and dopamine. The balance of these neurotransmitters can make depression more likely for some people.
Sex: Women are more often affected by depression than men.
Personality: People with certain personality traits may be more likely to have depression than others. For example, people who naturally feel angry, anxious, or self-conscious (traits of what’s sometimes called “neuroticism”) may be more at risk for depression.
Chronic stress or trauma: Different types of stress throughout your lifetime can affect your mental and physical health. There's some evidence that high levels of stress hormones may contribute to depression.
Illnesses: Scientists have shown that increased inflammation in the body, seen in conditions like autoimmune disease, may play a role in causing depression.
Chronic pain: Depression is common among people with chronic pain. This is partly due to the ways chronic pain affects many different parts of people’s lives. But chronic pain can also affect neurotransmitters and brain functions that may lead to depression.
Of course, even if you have many of the above risk factors, it’s important to remember that risk factors don’t equal diagnosis. Even if you have a lot of risk factors, it’s possible that you’ll never develop depression.
What should I do if I think I may be depressed?
Common symptoms of depression include:
Feelings of sadness, guilt, or worthlessness
Changes in sleep and appetite
Loss of pleasure in life
Fatigue or low energy
Physical restlessness or slowness
Difficulty concentrating
Thoughts of death or suicide
If you’ve been noticing these changes, consider reaching out to a healthcare professional. This is especially important if you’ve had symptoms for more than 2 weeks. A professional can diagnose you with depression, if appropriate. They can also rule out other medical conditions that may be affecting the way you feel. And they can point you toward the right treatment.
If you or a loved one has been having thoughts of suicide, get help right away. You can call 911 or go to the emergency room. Or you can reach out to the National Suicide Prevention Lifeline at 988.
Frequently asked questions
Postpartum depression (PPD) is when you experience depression after giving birth.
The biggest risk factor for PPD is having depression during your pregnancy. But postpartum depression is linked to many other things too, including your genetics. It also may be related to emotional, hormonal, and social changes that happen after your baby is born.
Bipolar disorder is a mental health condition that causes mood episodes, including depression. Just like depression, there are many genes linked to bipolar disorder.
Also, just like depression, there’s no single cause of bipolar disorder. A combination of factors seem to play a role — including genetics, your brain structure and chemistry, and your life experiences.
Postpartum depression (PPD) is when you experience depression after giving birth.
The biggest risk factor for PPD is having depression during your pregnancy. But postpartum depression is linked to many other things too, including your genetics. It also may be related to emotional, hormonal, and social changes that happen after your baby is born.
Bipolar disorder is a mental health condition that causes mood episodes, including depression. Just like depression, there are many genes linked to bipolar disorder.
Also, just like depression, there’s no single cause of bipolar disorder. A combination of factors seem to play a role — including genetics, your brain structure and chemistry, and your life experiences.
The bottom line
Depression is one of the most common health problems in the world. But the truth is: We don’t know exactly what causes it. It’s clear that depression is linked to many different genes. But other factors matter, too, like your physical health, brain chemistry, and even your life experiences.
And remember: Even if depression runs in your family, that doesn’t mean you’ll ever have it yourself. But it does increase your risk. If you’re concerned about depression, reach out to a healthcare professional. They can help you understand your risk factors and guide you toward treatment, if needed.
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References
American Psychiatric Association. (2024). What is depression?
Beurel, E., et al. (2020). The bidirectional relationship of depression and inflammation: Double trouble. Neuron.
Filatova, E. V., et al. (2021). Major depression: One brain, one disease, one set of intertwined processes. Cells.
Flint, J. (2023). The genetic basis of major depressive disorder. Molecular Psychiatry.
Klein, D. N., et al. (2011). Personality and depression: Explanatory models and review of the evidence. Annual Review of Clinical Psychology.
MedlinePlus. (2021). What is heritability?
Mental Health America. (n.d.). Basic facts about depression.
Shadrina, M., et al. (2018). Genetics factors in major depression disease. Frontiers in Psychiatry.
Sheng, J., et al. (2017). The link between depression and chronic pain: Neural mechanisms in the brain. Neural Plasticity.
Widiger, T., et al. (2017). Neuroticism is a fundamental domain of personality with enormous public health implications. World Psychiatry.
