In today's health matters, exercise can be as effective as a second medication for many people with depression whose condition hasn't been cured by a single drug.

University of Texas scientists found both moderate and intense levels of daily exercise can work as well as administering a second antidepressant.

The type of exercise needed however depends on the patient. Moderate exercise was more effective for women with a family history of mental illness.

Intense exercise was more effective with women who did not have a family history of the disease. For men a higher rate of exercise was more effective regardless.

Findings appear in the 'journal of clinical psychology.