Everyone experiences variations in mood - transitory blues, disappointments, the normal grief that accompanies the loss of someone you love. But a severe or prolonged depression
that interferes with the ability to function, feel pleasure, or maintain interest is not a mere case of the blues. It is an illness. Researchers have demonstrated that it results from biochemical imbalances in the brain.
In depression faith in deliverance, in ultimate restoration, is absent. The pain is unrelenting, and what makes the condition intolerable is the foreknowledge that no remedy will come not in a day, an hour, a month, or a minute. It is hopelessness even more than pain that crushes the soul.
-William Styron, 1990
Depression is one of the most common mental disorders affecting approximately 340 million people in the world. No one is immune from depression - it occurs in people of all social classes, all countries and all cultural settings.
One in four women and one in ten men can expect to develop depression during their lifetime, but it's not just adults who suffer. Depression affects at least one in 50 children under 12 and one in 20 teenagers.
A depressive disorder is an illness that involves the body, mood, and thoughts. It affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. A depressive disorder is not the same as a passing blue mood. It is not a sign of personal weakness or a condition that can be willed or wished away. People with a depressive illness cannot merely "pull themselves together" and get better. Without treatment, symptoms can last for weeks, months, or years.