Is depression genetic?

Genetic factors play an important role in major depression and bipolar disorder. These are illnesses in which familial patterns are often apparent, particularly in bipolar disorder, where a first-degree relative (a child) has an approximately 25 percent chance of having the disorder if one parent is afflicted and a 50 percent chance if both parents are. In major depression, the familial tendency is less marked. There are no particular preventive measures to be taken beyond this general advice: Pick your relatives carefully (especially your parents), try to avoid misfortune, enjoy good health, and live a good life. One might hope that an acknowledgment of heightened risk would be accompanied by greater insight into the nature of depression, its early recognition, and a lowering of the barriers to treatment.