Clinical and demographic differences between voluntary and involuntary psychiatric admissions in a university hospital in Brazil.

To assess the frequency of involuntary psychiatric hospitalizations from 2001 to 2008 and to determine associated clinical and socio-demographic characteristics, a retrospective cohort study was conducted. Adult admission data were collected from a university hospital in Brazil. Hospitalizations were classified as voluntary (VH) or involuntary (IH). Groups were compared using chi-square test for categorical variables and Mann-Whitney test for continuous non-parametric variables. The relative risk of certain events was estimated by the odds ratio statistic. Of 2,289 admissions, 13.3% were IH. The proportion of IH increased from 2.5% to 21.2% during the eight year period. IH were more frequently associated with female gender, unmarried status, unemployment, and more than 9 years of schooling. Psychotic symptoms were more common among IH. There were no differences in age, duration of hospitalization, or rate of attendance at first appointment after hospital discharge. Understanding of the characteristics associated with IH is necessary to improve the treatment of psychiatric disorders.