The conceptualization of an international consensus conference for the purpose of beginning to establish an operational definition for “behavioral disturbances of dementia” was born at the 7th International Psychogeriatric Association (IPA) Congress in Sydney, Australia, in November 1995. At that time, a special symposium on “research methodological issues in evaluating behavioral disorders of dementia” took place. From the high level of interest and attendance, it was clear that this matter was a source of great attention and concern by clinicians and researchers working with demented elderly. Although we have been aware that patients with dementias, including Alzheimer's disease (AD), manifest psychotic, depressive, and behavioral symptoms over the course of the illness, such symptoms until recently have elicited little interest or research support. Further, research was hampered by the absence of viable measurements and scales developed for this specific population. In addition, rigorous clinical trials were rare and virtually nonexistent in those with moderate and advanced dementias. Prior to 1992, only seven randomly assigned, double-blind trials in this population had been published, only one in a nursing home setting.