Why do some of us spend our lives grappling with chronic depression, while others never have a single depressive episode? With nearly 10 percent of Americans suffering from a depressive episode in any given year, depression is one of the most common mental disorders, and many of us assume that, like many chronic illnesses, it must be transmitted through our genes. But the actual answers about why some of us are touched by depression are much more complex.
The short answer is yes, some people are born with a genetic makeup that makes them prone to depression — but that doesn't mean they will automatically become depressed. It also doesn't mean that anyone born with a different genetic make up has lifelong immunity from the illness. Others can develop depression due to situational factors, and sometimes it's a combination of the two — a person can be born with a predisposition, but it takes an environmental trigger to set off the depressive episode.
Scientists are continuing to research all the possible causes of depression, which is important — the more knowledge we have, the more progress can be made in developing effective treatments for individuals who are suffering from depression. And it's not just about developing the best treatment, although that's certainly important. The more we learn about depression, the better we'll be able to help a loved one who is suffering from depression. And, if we find ourselves in a depressive episode, we'll be better able to treat ourselves with the compassion we deserve.
Based on the most up-to-date research, here are five key points about what causes depression, from genetics to life situations (and everything in between):
1. Genetics Have A Lot To Do With Who Gets Depressed
Recent research has found that 40 percent of people with clinical depression can trace it to a genetic link. Furthermore, an individual with a depressed relative is nearly five times more likely to suffer from depression than someone with a depression-free family tree. And if a member of your immediate family suffers from severe depression, you're about one and a half to three times more likely to develop depression than someone without a depressed family member.
A lot of the most informative research regarding the genetics of depression comes from studying identical twins, who are useful when studying genetics because they share the same genetic code. Researchers have found that if one identical twin suffers from depression, the other will also develop depression 76 percent of the time. Even when you adjust for environmental factors, like being raised in the same home, the numbers are still astounding — identical twins who are not raised together share clinical depression 67 percent of the time. These high rates definitely indicate that genetics are a huge factor. But since the rate isn't 100 percent, we can't deny that environmental factors are also at play.
2. Serotonin Levels Aren't The Sole Cause Of Depression
We've all heard vague statements about how depression is caused by "chemical imbalances" in the brain — and, on the surface, it makes sense. But have you wondered who these people are who have "balanced" chemicals in their brain? Well, you may have to keep wondering: many scientists agree that a perfectly balanced brain probably doesn't exist. We do know that faulty mood regulators in the brain contribute to depression, but the "serotonin imbalance" theory as most of us understand it is a gross oversimplification of how depression works — and one that leads many depression sufferers and medical professionals alike to overlook treatment methods like Cognitive Behavioral Therapy and other non-pharmaceutical options that have been shown to produce positive results.
3. Depression Can Be "Learned" From Family Members
We know that having a depressed parent or sibling increases our chances of developing depression ourselves — and a lot of that is due to sharing a genetic makeup. But depression can also be a "learned" behavior, especially when children grow up in a household where one or more of their immediate family members are suffering from severe depression.
Kids often mimic the behaviors of parents and older siblings, and even if they don't mimic, they tend to accept behavior seen in their homes as normal. This applies to many aspects of life — like how most of us spent our early childhoods thinking our parents were always right about everything.
So how does this apply to depression? Some researchers believe that kids with depressed family members may grow up thinking it's normal to have a depressed outlook on life, spend full days sleeping, shut down when life becomes overwhelming or engage in other depressive behaviors. Of course this isn't always the case — plenty of depressed parents are fully functional and engaged with their kids. But if side effects of their depression include unhealthy coping mechanisms, that's something children may incorporate into their own lives without even necessarily noticing it.
4. Some Forms Of Depression Are Situational
Even if you don't have the genetic makeup and the family history, you may still find yourself in the throes a depressive episode. There are multiple non-genetic causes of depression — and more will probably be discovered as research continues. Right now, some of the identified causes include being the victim of physical or sexual abuse, losing a parent early in life, suffering from a chronic physical illness, and experiencing physical and/or emotional neglect as a child. People who are under multiple stressors at once (i.e. home life and work life are simultaneously falling apart) are also more likely to become depressed.
The good news about situational depression is that because it can be traced to a tangible reason, you know what you need to be addressing in therapy. For example, if you've been the victim of violence, your depression is likely a side effect of PTSD — and 80 percent of PTSD sufferers recover with the right treatment. If you're drowning in stressful situations at home and at work, you can make life changes that will help you come out of the depressive episode. This is hard to do when you're feeling so down — but a therapist or other mental health professional can help you take steps to do things like find yourself a job in a healthier environment and deal with the stressors at home that are bringing you down.
5. Not All People With Genetic Predispositions End Up Depressed
It's also possible to be born with a predisposition for depression but to never actually become depressed. If someone with a predisposition manages to avoid things like bullying, illness, extreme stress at home and other common triggers of depression, they may end up going through life without a depressive episode.
So if you have a family history of depression, don't despair — it doesn't automatically mean you'll develop the illness. But the most important thing is to recognize the warning signs and seek help if you do have symptoms of depression. Over 80 percent of depressed individuals who receive treatment report that it's helpful, so regardless of the cause of your depression, it does not equal a life sentence of misery.