Depression is one of the most common diagnosable mental health conditions. There are loads of reasons you could become clinically depressed, including situational, genetic, and hereditary factors.
Is depression genetic or environmental?
Yes. No. Maybe?
It depends on who you ask and whose depression you’re talking about. There are multiple kinds of depression, and some have stronger ties to genetics than others.
Science has found some strong links between depression and genetics.
Major depression, or clinical depression, may be as much as five times more likely to occur in people who have relatives with depression than in those who don’t.
Heritability rates of major diagnosable depression could be as high as 31 to 40 percent, according to some studies.
It’s also possible to develop clinical depression without any external trigger.
Situational depression is the result of environmental factors. This is the kind of depression many of us experience in the worst moments of life, like getting dumped or losing a job.
So FFS, Greatist, do genetics cause depression or not?!
This question is a massive oversimplification of environmental vs. genetic depression. There’s no simple answer. Clinical depression can develop as a result of untreated situational depression.
A genetic predisposition to low moods could make environmental factors far more likely to trigger depressive episodes. But a loving home can break an intergenerational cycle of parental suicide.
In short, we still don’t know 100 percent whether genetics is the be-all and end-all of depression. We do know there’s a link in many cases.
Curing depression has proven to be hella difficult, because the condition is hella complex. No two cases are alike.
Whether you’re low on serotonin because you’ve seen some sh*t or depression has struck because your neurotransmitters are just being assholes, the results will be the same: depression rearing its ugly head.
Get ready to explore the genetic links and causes of clinical depression.
It might be in some cases.
In 2011, a team of British supernerds isolated a chromosome. You might wonder, what’s so special about that? British supernerds isolate chromosomes all the time. Well, this one is present in more than 800 families that have multiple members with depression.
They called this chromosome 3p25-26 (or Jeremy to its friends). More research is needed, but if it turns out that Jeremy is the so-called “sadness gene,” it would open up a whole new world of possibilities for treating or curing depression.
The same study estimated that up to 40 percent of folks with depression can point to some kind of genetic factor. And that rate skyrockets to 70 percent when looking only at the data from twins with major diagnosable depression.
Another review of 19 studies found a link between a different genetic variant — 5-HHTLPR — and major depressive disorder (MDD). The researchers found that this gene popped up more frequently in folks who had an MDD diagnosis.
What is 5-HHTLPR (or Kendall to its friends)? Well, Kendall possibly affects how well serotonin (a neurotransmitter that makes you feel good) travels throughout your brain.
But what about nature vs. nurture?
This is where the waters get murky. Because, yes, there is the sadness gene, and there are many documented instances of hereditary depression.
However, a lot of people in those studies also grew up in the same environment.
So while there may be a genetic link, there’s no way to prove that the younger generation didn’t “learn” depression by seeing how parents and other relatives dealt with difficult experiences and stress rather than genetically inheriting it.
Does gender play a part?
According to the numbers, yes. Some research from 2006 suggests that women are considerably more likely to develop some kind of hereditary depression.
But that gap is closing more each year. Depression in males is believed to be significantly underreported due to stigma around masculinity and showing emotions. (As of 2019, men in the United States were also more than 3.5 times more likely to die by suicide than women.)
Depression may also present differently in men than in women on average. There’s a growing movement to widen the diagnostic criteria so they include behaviors more typical of males with depression, like increased risk-taking and a higher tendency to self-medicate with drugs or alcohol.
A 2013 analysis using a wider range of criteria found the gender gap between rates of diagnosable depression to be much narrower — around 30 percent for men and 33 percent for women.
Most of the research on depression and gender is heteronormative. Studies that include trans and gender-nonconforming folks have found that their rates of diagnosable depression and/or anxiety could be as high as 52 percent (compared with 27 percent in cisgender peeps).
Serotonin makes you feel good. Literally. It’s the neurochemical that floats around your bod when you feel happy (alongside dopamine and a couple of others). Low serotonin levels are a key sign (and possible cause) of depression.
Both genetics and environment may affect serotonin levels. The environmental link is fairly obvious: When good things happen, you feel happy. That’s because serotonin is being released. Bad stuff = less serotonin.
Serotonin deficiency syndrome is a thing, and scientists don’t yet fully understand it. It can be caused by prolonged low serotonin levels in childhood due to abuse and trauma (meaning the brain doesn’t develop enough serotonin receptors).
But in other cases, the cause seems to be genetic. For reasons scientists don’t yet understand but really want to, some people seem to be born with brains that are not great at handling serotonin.
Inherited brain issues aren’t the only thing that can mess with serotonin. Serotonin is made in your gastrointestinal tract, and some genetic and hereditary digestive conditions can fudge your ability to produce it.
Your genes play a part in how much serotonin is knockin’ around in your noggin. The question for science right now isn’t if genetics f*ck with serotonin, it’s how, why, and how much.
Super common. There’s a large amount of the big sad out there.
According to the World Health Organization, 264 million people around the world have depression. If there really are 7 billion of us on this blue rock, that means about 3.8 percent of us are clinically depressed. Massive bummer.
In a national survey in 2019 (using data from that year only), 18.5 percent of adults in the United States reported that they’d experienced mild, moderate, or severe depression symptoms within the last 2 weeks.
It’s hard to estimate exactly how many people in the United States are living with depression at any one time. Data from the CDC suggest the figure could be about 8 percent of U.S. adults.
There are as many depression triggers as there are people living with depression. What triggers your depression will be unique to you.
But there are some consistent patterns among people who have depression that make identifying potential triggers a little easier (both for those with the condition and for the healthcare pros treating them).
Trauma is a common contributing factor to depression. The trauma may come from childhood events or experiences in adulthood. Abuse is a common form of trauma that leads to depression, as are difficult life events like divorce, loss of loved ones, serious illness, or injury.
Reminders of traumatic events can be a trigger for depressive episodes.
And it’s not unique to women — 8 to 10 percent of men may also experience baby blues after becoming a parent.
There are many, many other triggers. Illnesses like diabetes and cancer can lead to depression, as can substance misuse. As far as genetic triggers go, a whole bunch of research is happening right now to figure out exactly what they may be.
There’s no doubt that somewhere out there, right now, researchers are trying to think up ways to end depression forever.
But while there’s not yet a cure, treatment is absolutely possible. Treating depression can require both prescribed medication and significant lifestyle changes.
There’s no guarantee we can get rid of the condition permanently, though — recurrent depression (depression that just won’t go the f*ck away) is common.
According to some research, as many as 50 percent of those who recover from their first depressive episode will go on to have a second.
One day we may fully understand the underlying genetic causes of clinical depression and find a cure. In the meantime, medical treatment and community support are available to help folks living with the condition.
You can inherit a gene that may make you more likely to develop depression, but you can’t inherit the condition itself.
You’re also much more likely to develop depression if you pick up learned behaviors by growing up around folks who have it.
If a person with the depression gene is raised by relatives who experience depression and also have the 3p25-26 gene, their chance of developing depression is high.
But they inherit the gene, not the depression itself. Plenty of people in this exact scenario grow up to be depression-free adults.