Inflexibility or rigidity as a human characteristic exists throughout the life cycle and may get worse in some people as they age. Alternatively, old people are survivors, and survival usually means growing and adapting to a changing environment. Many elders learn the advantages of being flexible through experience. Most old people are depressed. Thus, although depression is a serious problem among the aged, most seniors are not depressed.
Most old people get senile.
In 1987, Ineichen reviewed 20 published studies of the prevalence of depression throughout the world in people over age 65. These studies varied greatly in their definition of dementia, sampling techniques, instrument sensitivity and statistical analysis. Thus, while dementia is a serious problem, no matter how you define it, most seniors are not senile. In psychiatry, diagnosis is predominantly based on extracting the longitudinal course of an illness. Therefore, access to a more extensive history can be a time-saving advantage.