Hoarding--the excessive acquisition of and failure to discard possessions, which preclude the appropriate use of living spaces--undermines safety and health by increasing risk for fire, falls, and infections. Hoarding does not result from deprivation early in life, nor are elders with hoarding behaviors merely "thrifty or frugal." Up to 64% of elders with hoarding behaviors have self-care deficits. Comorbid depression, anxiety, alcohol dependence, physical trauma, and damage to the prefrontal and orbitofrontal cortex are common. Hoarding was historically viewed as a variant of obsessive-compulsive disorder (OCD), but compulsive hoarding is a symptom in just 24% of all OCDs. Approximately half of elders with hoarding behaviors suffer from psychiatric conditions, mostly major depression and mood disorders. Treating elders with hoarding behavior in a medical-psychiatric model is a complex matter that may include prescription medication if an underlying condition contributes to the problem. Hoarding behavior results in placement in a nursing facility when squalor poses a health or safety issue.