A time-series test of the quarantine theory of involuntary commitment.

Persons believed to be mentally ill and imminently violent are often subjected to coerced treatment. Among the justifications for this practice is the argument that removing such people from the community is analogous to quarantine. We test the quarantine theory using daily data from San Francisco. Results suggest that the incidence of coerced treatment of males is inversely related to assaults and batteries by males one day later. The finding implies that persons who are involuntarily committed are at elevated risk of violent behavior. The implications of the findings for the prevention of assaultive behavior are briefly described.