Depression can be caused by external events such as trauma, grief, stress, difficult relationships, work environments, or situations over which you have no control. But it can also be caused by an internal response to biological factors including a genetic predisposition to depression.
Children, adolescents, adults, and older persons suffer from depression. Traumatic and stressful events - losing a job or a family member - can trigger depression. So can biological factors such as change in body chemistry or a physical illness.
We now know that depression is highly related to numerous physical problems - cardiac conditions, hypertension, headaches, chronic pain, and muscular-skeletal pain among others. While depression is more likely to strike those with a family history or those who previously have had an episode of depression, almost anyone can be a candidate for the onset of depression.