Walsh & Hoyt: Primary Degenerative Dementia

The term dementia refers to a variety of conditions in which there is cognitive impairment that involves several domains of cognitive function without a disturbance of consciousness. The cognitive deficits must include memory and may also include attention, language, behavioral, or visuospatial functions. Operational criteria have been derived, such as those of the Diagnostic and Statistical Manual of Psychiatry (DSM-IV) of the American Psychiatric Association. Cognitive impairment should be of sufficient severity to interfere with occupational or social function. In addition, the criteria require a normal level of consciousness to distinguish the condition from a confusional state. Dementia does not suggest a specific etiology. It may be reversible or irreversible and progress rapidly or slowly. It is a common medical condition, particularly in the elderly, with a prevalence rate of about 5% in the population over 65 years of age, rising to 20% in the group over 85 years of age.