In diagnosing depression, health care providers look for a person who has experienced several symptoms for weeks at a time. The provider will also do a physical exam and rule out other causes for the symptoms, which can include certain medications or medical conditions, NIMH says. Also people who are physically ill and who are not getting better often have an underlying depression. Medication, psychotherapy or a combination of both can be effective in treating depression. Mild cases of depression may be eased by psychotherapy alone. People with moderate to severe depression often are helped with antidepressant medication.

You can help prevent depression by staying active and being connected to other people through family, community activities, senior groups or church.

If you notice signs of depression in yourself, a friend or a family member, don't wait until it becomes severe. Discuss your individual needs with your health care provider, or talk to the person with depression, and encourage him or her to speak to a physician and seek treatment from a mental health professional.

Source: http://resources.purematters.com/healthy-mind/depression/depression-not-a-normal-part-of-aging