Although there are no specific genes that we can analyze and trace back to depression, if your family members have had depression, you're more likely to have depression as well. Clinical depression is a very common disease, so what causes depression? According to the National Institutes of Mental Health (NIMH), about 16.2 million U.S. adults will experience major depression in any given year. For some people, a disruptive or stressful life event, such as grief, divorce, illness, dismissal, and work or financial concerns, may be the cause.
Most people take the time to accept stressful events, such as grieving or the breakdown of a relationship. When these stressful events occur, the risk of becoming depressed increases if you stop seeing your friends and family and try to solve your problems on your own. You may be more vulnerable to depression if you have certain personality traits, such as low self-esteem or being too self-critical. This could be due to the genes you inherited from your parents, your early life experiences, or both.
Feelings of loneliness, caused by things like being apart from family and friends, can increase the risk of depression. You may be at higher risk of depression if you have a long-term or life-threatening illness, such as coronary heart disease or cancer. It is often said that depression is the result of a chemical imbalance, but that way of speaking does not capture the complexity of the disease. Research suggests that depression doesn't just come from having too much or too little of certain chemicals in your brain.
Rather, there are many possible causes of depression, including faulty mood regulation by the brain, genetic vulnerability, and stressful life events. A number of these forces are thought to interact to cause depression. It is estimated that between 10 and 15% of the general population will experience clinical depression throughout their lives. The World Health Organization estimates that 5% of men and 9% of women experience depressive disorders in a given year.