While the most serious of depressive illnesses in the elderly is major depressive disorder, patients' quality of life can be significantly impacted by dysthmic disorder, sub-threshold depression (minor depression), or a depressive disorder due to a general medical condition, all of which have been shown to be more prevalent than major depression in the community dwelling population of older adults. Older adults are also more likely to develop grief reaction and frequently deal with issues of bereavement. This review will discuss the diagnoses of all relevant depressive diagnoses that primary care physicians are likely to encounter. Among the many different assessment tools that screen for depression the briefest instruments are a two-question screening tool recommended by the U.S. Preventive Services Task Force and, specifically developed for older adults, the Geriatric Depression Scale (GDS) that is available in a short 15- Yes/No-question version. Many medical illnesses are associated with depressive symptoms. The focus in this review is on dementing illnesses/cerebrovascular disease, dementia of the Alzheimer's type, and Parkinson disease. First-line pharmacological therapy of depression includes selective serotonin inhibitors (SSRIs), and serotonin-norepinephrine reuptake inhibitors (SNRIs). Side effects of particular drugs can often be geared towards achieving additional benefits, e.g. weight gain associated with the use of some SSRISs may be helpful for patients with dementia.