Loss of mental functioning is one of the most distressing burdens of old age. The condition is progressive and irreversible and affects not only the victims but their families and society as a whole. Adequate research into causes and cures is lacking and as the old and very old come to define larger and larger segments of the population, the scope of the problem will inevitably grow.
There is a rise in the prevalence of mental illness in persons above the age of 65, as well as tendency for the rate of mental illness to vary with marital status: widowed persons, in particular, have a higher rate than married ones. More striking differences are found in relation to social class: there is a marked trend for the frequency of mental illness to vary inversely with social status. There is also a strong positive association found between mental disorder and physical handicap, which holds good for both men and women, and for all age groups over 65.