Depression in the third age represents one of the costliest conditions, as a result of the increased risk of suicide, somatic comorbidities, the decrease in daily functionality and the quality of life of both the patient and the family. According to statistical data, 12-45% of people over 65 suffer from depressive disorders, which often remain underdiagnosed. There is a close correlation between depression and somatic pathology in the elderly. Somatic conditions and depression potentiate each other and raise issues related to treatment modalities. Loss of social position, lack of social support and loneliness are among the most common causes of depression in the elderly. Characteristics of depression in the third age include: loss of interest in once enjoyable activities, feelings of helplessness, loss of hope that things can get better, slowness in movement, inactivity, irritability and sadness, sleep problems, pain, fatigue, weight loss, isolation from others or refusal to spend time with family, refusal to leave the house, ignoring household tasks, various anxiety disorders, suicidal ideation and behavior. About 40% of depression in the elderly is undiagnosed, and only one elderly person in seven with depressive symptoms receives appropriate treatment. Depression in the third age raises problems related to diagnosis, evolution and treatment. Affective disorders can have an important impact on the life of the elderly person and lead to the reduction of activities and loss of autonomy, up to a state of dependence on close people. Keywords: Depression; depressive disorders; elderly; the third age.