Old age is a worldwide and inevitable phenomenon, generally accompanied by a number of problems that the aged have to face and get accustomed to. Geriatric psychology and psychiatry emphasize the biological and psychological aspects of normal aging, the psychiatric effect of acute and chronic physical illness, and the biological and psychosocial aspects of the pathology of primary psychiatric disturbances of older age. The focus is on prevention, evaluation, diagnosis and treatment of mental and emotional disorders in the elderly. The most common mental and neurological disorders in this age group are dementia and depression.