Seeking to explain the difference in the frequency of hallucinations between Afro-Caribbean and White patients with dementia, Dr. Holmes stated that genetic differences are the most obvious explanation. The frequency of the polymorphisms is increased among Afro-Caribbeans, which is reflected in the incidence of schizophrenia in this population. Dr. Holmes also mentioned that serotonin receptor polymorphisms affect binding capacity to the sites, and are instrumental in forming visual hallucinations. He speculated that researchers will find that the different frequencies of behavioral and psychological symptoms of dementia (BPSD) in different countries will be largely accounted for by genetic variation in a number of polymorphisms. However, he emphasized the importance of using the same methodology so that results can be compared across countries and cultures. Dr. Cohen agreed that researchers should be investigating potential genetic differences. How the genetic traits are linked to neuropsychiatric symptoms is an interesting question, and requires a great deal more research.