Among clinicians, depression is shorthand for a debilitating syndrome - major depressive disorder - that robs people of their energy, their concentration, their memory, their restorative sleep . . . their ability to love and work and play. The disorder actually lights up the brain's pain circuitry, inducing a state of suffering far exceeding that of any physical discomfort. As one of my patients told me, "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."

To make matters worse, 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, including the hippocampus and prefrontal cortex. Simply put: depression causes brain damage.

And yet when people refer to depression in everyday conversation, they usually have something far less serious in mind. In fact, the term typically serves as a synonym for mere sadness. For example, I've heard people talk about feeling "depressed" after ripping a hole in a new pair of jeans, or even after missing an episode of their favorite TV show.  Such dysphoria - while unpleasant - 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. A little encouragement and support from loved ones is normally all it takes to restore our emotional equilibrium.

In contrast, clinical depression often persists for months on end, and a friendly word of support is simply not enough to loosen its suffocating grip. That's where the tragic confusion ensues. For when those suffering from depression confide their diagnosis to friends and family, they're often met with relative indifference, born of the assumption that the patient is afflicted with mere sadness - a condition from which they can quickly and easily recover. As a result, depressed patients are often encouraged to snap out of it. No one would dream of offering such cruel and ridiculous "advice" to someone diagnosed with cancer or heart disease; the admonition is equally inappropriate in the case of depression.

A few years ago, one of my patients suggested, "You shrinks really need to come up with a better name for this disease. Depression doesn't begin to describe what it's like, and the word is just way too confusing for people." I couldn't agree more. At least back in Freud's day - despite the field's many obvious shortcomings - clinicians actually had a precise technical term for depressive illness: melancholia. Perhaps it's time we brought this venerable term back into vogue - or coined an even better one. Such a simple step might go a long way toward increasing compassion for the millions who battle this devastating disorder.

Psychology Today