Depression is potentially life threatening disorders that affects hundreds of millions of people all over the world. It can occurs at any age from childhood to late life and is a tremendous cost of society as this disorders causes severe distress and disruption of life and, if left untreated, can be fatal.The etiology of depression in the elderly is poorly understood.depression may induce physical disability by reducing motivation for physical activity and subsequent de-conditioning in older people.Physical activity might be one of the most important behavioral interventions for preventing depression among older adults.