It’s the nature of language for words to evolve – and often times the power of their original meaning becomes lost through usage. Case in point: “depression.” As in, “I’m so depressed that my team didn’t win,” or, “I’m so depressed because I lost my bracelet.” Of course you may be sad when these things happen, but clinically depressed? Probably not.

Stephen Ilardi, Ph.D. – nationally recognized researcher on depression and author of "The Depression Cure" – writes in Psychology Today that “depression” is one of the most tragically misunderstood words in the English language. While fleeting sadness is unpleasant, he writes, it “is simply part of the human condition, a hard-wired reaction to negative life events. But it has little effect on our ability to function, and it rarely lasts for long.”

Depression, on the other hand, is a serious medical illness that involves the brain, notes the U.S. National Library of Medicine. “It's more than just a feeling of being "down in the dumps" or "blue" for a few days. If you are one of the more than 20 million people in the United States who have depression, the feelings do not go away.” The consequences of the disease can be devastating, as we have just seen with the suicide of actor Robin Williams, who had been “battling severe depression,” according to his publicist.

So what does actual depression look like?

In its most official definition, to be diagnosed with depression you must have five or more of the following symptoms – over the course of at least two weeks – described in the Diagnostic and Statistical Manual of Mental Disorders (DSM). This is the handbook published by the American Psychiatric Association and used by mental health providers to categorize mental conditions.

  • Depressed mood, such as feeling sad, empty or tearful (in children and teens, depressed mood can appear as constant irritability)
  • Significantly reduced interest or feeling no pleasure in all or most activities
  • Significant weight loss when not dieting, weight gain, or decrease or increase in appetite (in children, failure to gain weight as expected)
  • Insomnia or increased desire to sleep
  • Either restlessness or slowed behavior that can be observed by others
  • Fatigue or loss of energy
  • Feelings of worthlessness, or excessive or inappropriate guilt
  • Trouble making decisions, or trouble thinking or concentrating
  • Recurrent thoughts of death or suicide, or a suicide attempt
In addition, to help differentiate depression from ordinary fluctuations in mood, there must be significant impact on social, professional, or other important areas of your life.

The exact causes of depression are not precisely understood, but a number of factors may make depression more likely. Depression is often blamed simply on a “chemical imbalance,” but the complexities of the disease go far beyond that tidy summary. While research confirms that chemicals are involved in depression, it’s not just “too much of this and not enough of that.” As described by the Harvard Medical School, “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.” They add, “depression has many possible causes, including faulty mood regulation by the brain, genetic vulnerability, stressful life events, medications and medical problems. It’s believed that several of these forces interact to bring on depression.”

Ilardi takes this a step further by noting that depression is neurotoxic. “By suppressing levels of a key neural growth hormone (BDNF), the disorder leads to the eventual death of neurons in critical memory and reasoning areas of the brain,” he says, “including the hippocampus and prefrontal cortex. Simply put: depression causes brain damage.”

He goes on to explain that depression can actually “light up the brain’s circuitry,” resulting in anguish that goes beyond that of any physical discomfort. As one of Ilardi’s patients told him, "If I could give up my right arm – literally, have it amputated – to escape the pain of depression forever, I would take that deal in a heartbeat."

With that in mind, the next time rain ruins the weekend plans, we'll be sure to qualify it as "sad," rather than "depressing." Fortunately we've come a long way in treating this potentially debilitating illness. If you or someone you know appears to be suffering from the symptoms listed above, there's help. Talk to your doctor. Early diagnosis and treatment help keep depression from getting worse or lasting a long time; and regardless of when depression is diagnosed, treatment can help people get their lives back on track.

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