The elderly are the fastest growing segment of the global population with the number of people age 60 or older having doubled since 1980 and the number of people age 80 or older expected to increase more than 4-fold (to 395 million) by the year 2050. While depression is overall less common in older people compared to younger people, there are sub-groups of elderly, such as those with significant medical comorbidity, who are at greatly elevated risk for depression. Negative consequences of late-life depression include functional decline and disability, increased use of non-mental health services, increased mortality rates due to cardiovascular causes, increased cancer rates, and substantially greater risk for suicide. Geriatric suicide is a global epidemic, which is worsened in many countries and cultures by socioeconomic disparities and cultural/social upheaval. Geriatric depression should be carefully assessed and treated. Treatments for geriatric depression include biological modalities such as antidepressant medications and Electroconvulsive therapy (ECT) as well as psychotherapy and psychosocial interventions. When they are prescribed pharmacotherapies for depression, older adults are especially likely to experience adverse drug effects as a result of their multiple chronic diseases, use of multiple concomitant medications, and the pharmacokinetic and pharmacodynamic changes that accompany aging. Antidepressants that minimize side effects are generally preferred in elderly individuals although the expected therapeutic response to drug treatment is generally modest. Psychosocial and psychotherapeutic measures can also be effective in late-life depression. Complexities of assessment and treatment include the risk of missing a bipolar depressive diagnosis, which would contra-indicate the use of antidepressant monotherapy. Given the projected increased proportions and overall numbers of older people with mental disorders there is a need for all clinicians to be familiar with mental health issues in elderly patients.