Much research has focused on neurochemical and neuropathologic changes in dementia. However, further research is required before definite conclusions can be made about the link between these neurochemical and neuropathologic changes and specific behavioral and psychological symptoms of dementia (BPSD) (Zaudig, 1998). Similarly, the relationship between cognitive status and BPSD has yet to be clarified. Studies investigating the relationship between cognition and BPSD have yielded little consensus, ranging from no association to positive, negative, or mixed findings (Chen et al., 1998). Examples include differences in findings from studies relating the occurrence of psychosis to the severity of cognitive deficits (Ballard & Oyebode, 1995; Molchan et al., 1995; Wragg & Jeste, 1989); failure of some often-quoted associations, such as a relationship between psychosis and the rate of cognitive decline, to hold up under a rigorous critical appraisal of the published data; and contradictory findings regarding the effects of antidepressant treatment on cognition in patients with concomitant dementia and depression (Greenwald, 1995).