It is estimated, for example, that more than 330 million people worldwide suffer from serious depression, a condition characterized by overwhelming sadness and a loss of pleasure in everyday activities. It has been estimated that in 20 years, depression will be outranked only by cardiovascular disease. Little wonder that it has been called “the common cold of mental illness.”

Depression​—Overwhelming Sadness

Most of us know what it is like to experience a wave of sadness. In time​—perhaps in just a matter of hours or days—​the feeling subsides. Clinical depression, however, is far more serious. In what way? “Those of us who are not depressed know that the rides our emotions take us on eventually end,” explains Dr. Mitch Golant, “but the depressed individual experiences the ups and downs, twists and turns of his feelings as if on a runaway train without a clear sense of how or when​—or even if—​he can ever get off.”

Clinical depression can take many forms. Some people, for example, have what is called seasonal affective disorder (SAD), which manifests itself during a particular time of year​—usually winter. “People with SAD report that their depressions worsen the farther north they live and the more overcast the weather,” says a book published by the People’s Medical Society. “While SAD has been linked mainly to dark winter days, in some cases it’s been associated with dark indoor work spaces, unseasonable cloudy spells and vision difficulties.”

What causes clinical depression? The answer is not clear. While in some cases there seems to be a genetic link, in most instances life experiences appear to play an important role. It has also been noted that it is diagnosed in twice as many women as men.a But this does not mean that men are unaffected. On the contrary, it is estimated that between 5 and 12 percent of men will become clinically depressed at some point in life.

When this type of depression strikes, it is all-pervasive and affects virtually every aspect of one’s life. It “shakes you to the core,” says a sufferer named Sheila, “corroding your confidence, self-esteem, your ability to think straight and make decisions, and then when it reaches deep enough, it gives a few hard squeezes just to see if you can hold on.”

There are times when a sufferer can gain much relief by talking out his or her feelings with an empathetic listener. (Job 10:1) Even so, it must be acknowledged that when biochemical factors are involved, depression cannot simply be willed away with a positive outlook. Really, in such a case, the dark moods of this illness are beyond the sufferer’s control. Furthermore, the sufferer may be as baffled by the condition as family members and friends are.

Consider Paula,b a Christian who endured crippling episodes of intense sadness before her depression was diagnosed. “Sometimes after Christian meetings,” she says, “I would rush out to my car and weep, for no reason at all. I just had this overwhelming sense of loneliness and pain. Although all the evidence showed that I had many friends who cared for me, I was blind to it.”

Something similar happened to Ellen, whose depression required that she be hospitalized. “I have two sons, two lovely daughters-in-law, and a husband​—all of whom I know love me very much,” she says. Logic, it seems, would tell Ellen that life is good and that she is precious to her family. But on the battlefield of depression, dark thoughts​—no matter how irrational—​can overwhelm the sufferer.

Not to be overlooked is the significant impact that one person’s depression can have on the rest of the family. “When someone you love is depressed,” writes Dr. Golant, “you may live with a chronic sense of uncertainty, never really knowing when your loved one will recover from a depressive episode or fall into a new one. You can feel profound loss​—even grief and anger—​that life has deviated, maybe permanently, from the norm.”

Often, children can detect a parent’s depression. “A depressed mother’s child becomes highly attuned to his mother’s emotional states, carefully observing every nuance and change,” writes Dr. Golant. Dr. Carol Watkins notes that children of a depressed parent are “more likely to have behavioral problems, learning difficulties, and peer problems. They are more likely to become depressed themselves.”