It's not known exactly what causes depression, but various factors are believed to be involved. (Photo: Wstockstudio/Shutterstock)
With the recent suicides of designer Kate Spade and chef Anthony Bourdain, depression awareness has skyrocketed. The headlines are full of tips for recognizing signs of depression in others or dealing with feelings of depression yourself.
But what causes those feelings? You may have heard depression is caused by a "chemical imbalance" in the brain, but that idea is simplistic and doesn't nearly capture what can trigger the mood disorder marked by such persistent, strong feelings of sadness.
"To be sure, chemicals are involved in this process, but it is not a simple matter of one chemical being too low and another too high," according to Harvard Health.
"Rather, many chemicals are involved, working both inside and outside nerve cells. There are millions, even billions, of chemical reactions that make up the dynamic system that is responsible for your mood, perceptions, and how you experience life."
It's a complex formula, as other possible causes of depression are physical and environmental, biological and psychological.
Causes of depression
From steroids to high blood pressure pills, many medicines list depression as a possible side effect. (Photo: Pavel Kubarkov/Shutterstock)
From physical factors to emotional situations, there are many factors that are believed to play a role in depression.
Genetics — If someone in your family has depression, that may increase your risk of having it, too. Children, siblings and parents of people with severe depression are somewhat more likely to be depressed than members of the general population. Like most psychiatric disorders, the genetics of depression are not simple and straightforward, says WebMD. Researchers are trying to isolate genes that may contribute to depression.
Brain chemistry and makeup — Researchers have found differences in the brains of people who have depression vs. those who don't. The hippocampus, a small part of the brain that is key for memories, seems to be smaller in some people with depression than those who have never been depressed. Nerve cell connections, nerve cell growth, nerve circuits and neurotransmitters in the brain all are believed to play a role in depression, according to the Mayo Clinic.
Medications — Symptoms of depression can be a side effect of many drugs, such as steroids and blood pressure medications. A recent study found that more than one-third of adults in the U.S. may be using prescription medications that can cause depression or increase the risk of suicide. The researchers found more than 200 drugs — including birth control pills, heart medications, antacids and painkillers — list depression or suicide as possible side effects.
Stressful events — Good and bad major experiences — from a new job to the loss of a loved one — can trigger feelings of depression. So can moving, a serious illness, the end of a relationship, physical or sexual abuse, and financial problems. Everyone has to tackle stressful situations in life and most people don't develop mood disorders, points out Harvard Health, but stress plays a key role in depression.
Loneliness and social isolation — People who are depressed are more likely to avoid contact with friends and family. But being isolated and feeling lonely can also trigger bouts of depression.
Substance abuse — Alcohol or drug abuse can trigger depression. According to WebMD, nearly 30 percent of people with substance abuse problems also experience depression.
Other mental or physical disorders — Sometimes depression goes hand-in-hand with a serious physical illness such as cancer, chronic pain or heart disease. A history of another mental health disorder, such as anxiety disorder, post-traumatic stress disorder or an eating disorder can also trigger depression.
Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.
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