Certain conditions and medication effects may mimic Dementia. The most common one is depression. Patients with depression frequently complain of problems with cognition and memory. The depression may not even be recognized, or not seem to be as severe as the cognitive complaints. This condition has been termed “pseudodementia” and is the most frequently identified treatable cause of cognitive difficulties. Because of this, depression must be ruled out before making a diagnosis of Dementia: it may be impossible to diagnose early Dementia in patients with depression until the depression is treated.

Medications may also cause significant cognitive impairment as a side effect. The most common offending medications include medications with anticholinergic effects, benzodiazepines (sleeping pills, antianxiety medications such as valium), and pain medications. All of these become more of a problem as people get older and they are less able to effectively metabolize these drugs. In evaluating patients for Dementia an assessment of medications is one of the first steps.

Elderly patients may also have a sudden and substantial decline in cognition if they get infections of the lungs or urinary tract which may appear to mimic Dementia but appear much more suddenly and gradually clears as the infection is treated.