Major depression may strike once in a lifetime, but many people experience 2-3 episodes, and some many more throughout their lives. Depression typically lasts an average of 8-9 months, but can range in duration from one month to one year. About twice as many American women experience major depression than American men. The disorder differs from bipolar disorder or manic depression during which people experience happy or euphoric moods in addition to depression. However, in both bipolar and major depression, scientists speculate that an imbalance of chemicals in the brain impacts mood control to trigger the disorders.
Some evidence points to a genetic cause for the chemical imbalance.
For example, identical twins are four times more likely to suffer major depression when one twin is depressed than non-identical ones. While depression may have genetic causes, it is still treatable. The NDSD screen may give you a glimpse of what psychotherapy could do for you. You would talk first to a counselor, undergo preliminary testing, and then watch a video that describes depression. Afterwards, you would meet with the counselor again to see if there is a need for further treatment.