ABSTRACT
According to DSM IV-TR criteria (2000), disorders of dementia are characterized by memory and multiple cognitive deficits but are classified as different disorders based on etiology (e.g., general medical condition, cerebrovascular disease, substance inducement). Prevalence estimates of dementia vary depending on the subjects sampled, type of dementia, severity of impairment, and regions or countries studied, but according to the DSM IV-TR, 3% of the adult population suffers from severe cognitive impairment. In clinical and hospital-based studies, nearly half of all dementia cases are of Alzheimer’s type; population-based studies report even higher rates (e.g., Edland, Rocca, Petersen, Cha, & Kokemen, 2002). Prevalence rates of dementia in nursing home residents from other countries such as Durango City, Mexico, were reported as 16.1% with the majority (11.6%) suffering from Alzheimer’s disease. Based on a random sample of 1,062 residents age 70 or older in southeastern France, dementia was found in 9.2% of the cases; 5.5% were of Alzheimer’s type (Obadia et al., 1997). Baiyewu, Adeyemi, and Ogunniyi (1997) reported that the majority of psychiatric disorders in Nigerian nursing home residents were dementia cases, and Snowdon and Lane (2001) reported that the prevalence of dementia among elderly people living at home in Botany, Australia, was 11%. Recently, Meguro et al. (2002) reported that the overall prevalence rate in adults 65 and older living in Tajiri, Japan, was 8.5%. Collectively, these studies substantiate that dementia occurs in a significant portion of adults worldwide, especially dementia of Alzheimer’s type.
