Large discrepancies in psychiatric compulsory admission rates have been found in the different European countries. However, some trends seem to exist in most studies: compulsorily admitted patients are more frequently male, unemployed, with a lower level of education, are more likely to belong to racial minorities (mainly black), and the most frequent diagnosis is schizophrenia.

To compare demographic and clinical characteristics of patients voluntarily and compulsorily admitted to a Portuguese psychiatric unit.

Retrospective data of all the patients admitted to a psychiatric inpatient unit, from January 2004 to December 2007, were reviewed. The demographic and clinical characteristics of compulsorily and voluntarily admitted patients were compared.

In a total of 1434 admissions, 180 were compulsory (11.2%). Compared to voluntarily admitted patients, those admitted compulsorily were significantly younger (38.2 vs. 43.6 years), more frequently male (62.8 vs. 47.1%), and black (27.8% vs. 19.9%), received more often a diagnosis of schizophrenia (34.4 vs. 19.0%), and had a longer average length of stay (27.0 vs. 18.5 days). There were no statistically significant differences in the seasonality of admissions or the number of readmissions in both groups.

The results are similar to those obtained in other studies, except for a higher rate of compulsory admissions. That can be explained by, among other factors, the low socioeconomic level and high percentage of immigrants in the local population. The comparison with voluntarily admitted patients helps identify characteristics associated with the two groups.