Depressive syndromes and dementia are the most frequent psychiatric disorders in the elderly. Reactive depressive syndromes can be associated with the restriction of social competence due to increasing multi-morbidity, loneliness, social isolation, the consequences of retirement, interpersonal conflicts, and the loss of partners or close relatives. Endogenous depressive syndromes in the elderly are frequently combined with diffuse and changing somatic complaints, psychomotor restlessness and agitation. Furthermore, depressive syndromes can be caused by somatic illness, degenerative disorders, other organic diseases or certain drugs. The presence of simultaneously occurring somatic illness, positive family history, certain personality traits, and severity of disease could exert an adverse influence on clinical outcome. Medical treatment should consider the special pharmacological features of old age, and should be combined with psychotherapy as well as a close involvement of the relatives.