Depression is a common condition in older people, affecting in its moderate or severe forms around 4 % of those living in the community. Depression has been shown to also increase the rate of mortality. However, far less is known about depression in old age than in younger or middle age. Depression in the old differs from younger patients in several aspects: comorbid medical conditions, polypharmacy, alterations in age-associated organ function and pharmacodynamic and pharmacokinetic changes and a higher level of drug interactions. These patients also have a higher risk of medication side effects. However, treatment is effective and maintenance therapy can successfully prevent recurrence of depressive episodes. Selective serotonin reuptake inhibitors (SSRI) and selective serotonin-noradrenaline reuptake inhibitors (SNRI) are recommended as first-line treatment for the acute phase and continuation therapy. At least 6 weeks of treatment is necessary to assess the therapeutic effect. Lithium augmentation has been shown to be effective in treatment-refractory depression. Continuation therapy is recommended for at least 9 months and duration of maintenance therapy should be at least 2 years.