An analysis of memory loss in dementia and depression.
Degree GrantorUniversity of Canterbury
Degree NameMaster of Arts
Previous studies comparing memory loss in dementia and depression have been criticised for failing to equate for differences in initial learning ability. The purpose of this study was to see if elderly depressed subjects would demonstrate a normal "U" shaped serial position curve (i.e. the tendency to show increased recall of items at the beginnings and endings of lists) after their level of recall was reduced to the same level as subjects with dementia by decreasing the time to study each item. Groups of normal (N=20), depressed (N=20) and dementing (N=20) subjects were examined for their ability to remember serially presented words and pictures. The results of analyses revealed that while depressed subjects showed significant memory loss, pattern of memory recall clearly distinguished them from the demented group. In comparison to the dementia sample, depressives continued to show a robust "primacy effect" (i.e. better recall of words from the beginnings of lists). Results were consistent for both visual and verbal modalities. This finding is in accord with previous research suggesting that memo,ry loss experienced in depression is characteristically different from that found in dementia. The serial position paradigm may be clinically useful for distinguishing patients with early dementia from elderly depressed patients with memory deficits.