9 Sneaky Causes Of Depression

From the weather to your lifestyle habits.

11/12/2015 06:00 am ET | Updated Nov 13, 2015

For some people, sub-zero temperatures aren't the only difficult side effect of winter. Approximately 10 million Americans also experience seasonal affective disorder, a depression-related mental health condition that waxes and wanes depending on the time of year.

In most instances, the disorder begins around the last leg of fall and lasts through the spring. It's typically prevalent among people in northern states that are cloudier, colder and darker for extended periods of time.

Unfortunately, the changing season isn't the only surprising cause of depression. There are some triggers -- including lifestyle habits -- that can prompt the condition.

"Depression comes in many forms. It can be mild and people can be functional, or it can be severe and debilitating," Josie Znidarsic, a family physician at the Cleveland Clinic's wellness institute, told The Huffington Post. "It can happen to anyone. ... A major life trauma doesn't have to occur to have depression. It's also not something that will just disappear if you ignore it."

Of course, there are instances where the mental health condition isn't caused by any external circumstances. Some people's brain chemistry, hormones and genetic inheritance from family members can also be a large factor. That said, there are times when an outside trigger can contribute to the development of the mental illness. Below are a few surprising contributors to depression.

Tara Moore via Getty Images

1. Chronic illness

Dealing with chronic disease isn't just tough physically, but emotionally as well. People who suffer from a chronic condition like heart disease, diabetes and cancer are more likely to experience depression, according to the Centers for Disease Control and Prevention. It's important to note that scientists have yet to determine which one may cause the other, but experts stress that there are specific ways to manage the mental health disorder while working through chronic illness.

2. Smoking

Here's a good reason to kick that habit to the curb: A 2015 British study found that smokers were more likely to suffer from anxiety and depression overall than non-smokers. Additionally, the study found that smoking may be a source of anxiety because of the feelings of withdrawal smokers experience after not having a cigarette, the researchers said. 

"That 'high' you get from cigarettes isn't useful because it's destructive to your body," Cleveland Clinic's chief wellness officer Michael Roizen previously told HuffPost. "You want to figure out what will give you a 'high' that isn't damaging or contributes to disease. Do that by finding a passion you love, whether it's exercise, talking with a friend or cooking. That's going to help, particularly when it comes to depression."

3. Excessive social media use

Social media is just a glimpse of someone's life through a glass half full; it does not accurately portray someone's reality. But you still may find yourself stacking your life against theirs. This is subconscious process is what researchers call "social comparison," and it can lead to feelings of depression, according to a study published in the Journal of Social and Clinical Psychology.

4. Your neighborhood

Are you a city dweller or a country resident? It could make a difference in your mental health. Research shows that people who live in urban areas may be more susceptible to mental illness, particularly depression, Scientific American reported. While researchers say the underlying cause of why that happens is incredibly complex, they theorize that spending more time in nature can be a helpful antidote.

5. Diet

Your physicality and mentality may be tied to what you consume. Research suggests that people who have a poor diet -- think foods high in processed meats, sugar and fat -- also were more likely to report symptoms of depression, the Mayo Clinic reported. A 2008 data analysis published in the Indian Journal of Psychology states that "nutrition can play a key role in the onset as well as severity and duration of depression."

This, of course, is cyclical. Depression also can result in a change in appetite, sometimes making it difficult for a person to have proper nutrition. Experts say that the relationship is complex, but it's still something to be aware of when it comes to your mood.

6. Too much sitting

The only avenue to a healthy body and mind is not only to prioritize what you eat, but how much activity you do. Research shows exercise can boost your mood. Not only that, the opposite behavior of too much inactivity may be linked to experiencing symptoms of depression. Time to move those feet.

7. A lack of sleep

Sleep deprivation is no joke. If you don't prioritize those Z's, you're not only at risk for chronic conditions like heart disease, you're also at risk for emotional conditions. Research shows severe sleep loss can mess with your mood. Depression also can impact your sleep, creating a vicious cycle.

8. Brain inflammation

Emerging research is finding that depressive symptoms may be due to a "neuroinflammation," or a natural response the brain engages in to protect itself. A study published in the journal JAMA Psychiatry found that brain inflammation was 30 percent higher in depressed patients. This may be good news when it comes to stigma, given that the common misconception about depression is that it's something a person can "just get over" or that they "brought it on themselves."

9. Not putting your needs first

If you prioritize others and ignore your own needs, that can take a toll on your mental health. "Too often people leave no space or time to take care of themselves," Znidarsic said. "If they don't have the ability to say no to people or things that don't nurture them, that can really leave someone drained and depressed."

If you feel like you may be experiencing depression, hope is certainly not lost, Znidarsic stressed. There are ways to manage it to help you get back into a better frame of mind -- because you deserve to be healthy.

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