Question:
Depression, subcortical dementia and normal aging: all three may havesimilar neurobehavioral manifestations. So how does a clinician make adifferential diagnosis?

So Is It Depression or Is It Dementia? Can anyone give me some suggestions???

Or can anyone share with me some knowledge on this or source of information??

Answer: Speaking at the recent U.S. Psychiatric & Mental Health Congress,Wilfred G. Van Gorp, Ph.D., associate professor and director of theneuropsychology program at Cornell University, offered some guidelines.He began by reviewing the neuropsychological changes associated withnormal aging. Crystallized intelligence-those verbal abilities that dealwith long-held knowledge-tends to be resistant to change following anykind of brain perturbation or central nervous system (CNS) stressor, hesaid. This remains relatively stable until a person reaches theirmid-60s. In contrast, fluid intelligence-psychomotor speed andnonverbal, often visuospatial tasks-is more susceptible to CNS changes.These nonverbal abilities, typically those that are timed and involvepsychomotor speed, have a more precipitous decline, beginning after age40. The fragility of certain cognitive tasks, as measured by the timedperformance subtests on IQ tests, has been called the classic agingpattern, Van Gorp said.He presented study data showing that changes in the frontal part of thebrain and the subcortical structures are likely responsible for thiscognitive decline of aging. To further explore this pattern, he and hiscolleagues compared normal elderly individuals to patients with AIDSdementia complex. They reported a remarkable similarity of both patternand level of performance on every neuropsychological test. The normalelderly, who had an average age of around 75, resembled, in both leveland pattern of cognitive functioning, the 35- and 40-year-old patientswith HIV dementia.

What does this mean? When evaluating an elderly patient, the clinicianfirst has to determine whether the symptoms are caused by normal aging.This means embarking upon a battery of neuropsychological tests withnorms to compare with other people in the same age group. The clinicianexperienced in working with older adults can also give a mental exam andcompare to see if it is a deviation from normal aging or not.Before surveying the literature about the cognitive manifestations ofdepression and comparing these manifestations to dementia symptoms, VanGorp stressed the difficulty of interpreting that literature. Themajority of the cognition and depression studies conducted around theworld have looked at depressed patients who have neurologic illnesses,such as Parkinson's disease, stroke or progressive supranuclear palsy,any of which may have caused the depression. Ruling those out leavesonly 13 qualified studies that focus solely on cognition and depression.