Psychiatric disorders in older patients can be lifelong or begin in later life. Those beginning in later life are sometimes associated with dementia, delirium, and stroke/brain vascular disease but are often idiopathic. In general, the same psychological and pharmacologic treatments that are effective in younger individuals have similarly efficacy in the elderly, but the presence of structural brain disease and comorbid physical illness are risk factors for poorer response. Antidepressants are effective therapies for major depression and often require the same doses as in the young. Antipsychotics should be used sparingly and at as low a dose as possible. Benzodiazepines should be avoided if possible.