age-related cognitive decline. as people age they usually experience slower information processing and mild memory impairment. in addition their brains frequently decrease in volume and some nerve cells or neurons are lost. these changes called age-related cognitive decline are normal and are not considered signs of dementia. mild cognitive impairment. some people develop cognitive and memory problems that are not severe enough to be diagnosed as dementia but are more pronounced than the cognitive changes associated with normal aging. this condition is called mild cognitive impairment. although many patients with this condition later develop dementia some do not. many researchers are studying mild cognitive impairment to find ways to treat it or prevent it from progressing to dementia. depression. people with depression are frequently passive or unresponsive and they may appear slow confused or forgetful. other emotional problems can also cause symptoms that sometimes mimic dementia. delirium. delirium is characterized by confusion and rapidly altering mental states. the person may also be disoriented drowsy or incoherent and may exhibit personality changes. delirium is usually caused by a treatable physical or psychiatric illness such as poisoning or infections. patients with delirium often though not always make a full recovery after their underlying illness is treated.
what conditions are not dementia?