Although precise statistics aren't known, depression is considered relatively common. In any given year, about 12 million adults in the United States have depression. Depression cuts across all racial, ethnic and economic divides — no one is immune from the risk of getting depression.
Depression typically begins in the late 20s, but it can arise at any age, affecting everyone from young children to older adults. Twice as many women are diagnosed with depression as men, but this may be due in part because women are more likely to seek treatment for depression.
Although the precise cause of depression isn't known, researchers have identified certain factors that seem to increase the risk of developing or triggering depression, including:
* Having other biological relatives with depression * Having family members who have taken their own life * Stressful life events, such as the death of a loved one * Having a depressed mood as a youngster * Illness, such as cancer, heart disease, Alzheimer's or HIV/AIDS * Long-term use of certain medications, such as some drugs used to control high blood pressure, sleeping pills or, occasionally, birth control pills * Certain personality traits, such as having low self-esteem and being overly dependent, self-critical or pessimistic * Alcohol, nicotine and drug abuse * Having recently given birth * Being in a lower socioeconomic group