Hospitalization for mental illness: evaluation of admission trends from 1941 to 1971.

A study of the diagnostic composition of the inpatient population of Ontario and Canadian psychiatric facilities has shown an important change in hospital-treated illness over the period 1941-71. Patients with nonpsychotic disorders accounted for 54% of all admissions to Ontario public mental hospitals in 1971, compared with only 8% in 1941. The trend was similar for both first admissions and proportion of readmissions, and was similar for psychiatric units of general hospitals. In contrast, the overall rate of first admission for psychotic disorders to inpatient facilities remained remarkably constant over time, as did the proportion of readmissions among all admissions. The findings dispel the notion that the increasing proportion of readmissions is due largely to a rapid turnover of former long-stay psychotic patients (the "revolving-door phenomenon"). The findings could not be attributed to a changing prevalence of types of psychiatric illness, increased availability of psychiatric inpatient facilities or comprehensive medical insurance.