Christensen EM, Bengtsson Å, Kramp P, Rafaelsen OJ. Involuntary commitments in Denmark and Sweden. The differences in frequency illustrated by comparison of two local areas in the two countries. Involuntary commitment to a psychiatric institution is some ten times more frequent in Sweden than in Denmark. Three factors are probably of importance to explain this difference: 1) In Sweden patients may be involuntarily committed to a psychiatric institution for social reasons, and this indication accounted for 57% of the Swedish cases investigated. In Denmark patients cannot be involuntarily committed for social reasons. 2) In Sweden patients may be discharged on probation. In such a probation period a patient may be returned to the psychiatric institution in accordance with the hospital psychiatrist's decision. Forty per cent of the Swedish patients were readmitted in this manner. 3) In Sweden patients may be involuntarily committed even if they do not resist hospitalization; 74% of the Malmö patient sample did not directly resist hospitalization, and this is taken as a tendency towards "prophylactic" involuntary commitment. In Denmark patients may be retained in accordance with the hospital psychiatrist's decision independent of whether they have entered the psychiatric institution voluntarily or involuntarily. This is not possible according to Swedish legislation. The Swedish non-objecting patients entering the hospital under "involuntary" status and the Danish patients being refused discharge were similar in terms of diagnosis. Involuntary commitment on social indications, discharge on probation, and legislative barring of retention of voluntarily admitted patients tend to increase the number of patients involuntarily committed.