The majority of assaults occur when patients are crowded together with little structured activity and when staff demand activity from them. One particular high-risk time for assaults is just after meals when patients are milling in corridors. A small proportion of patients account for a disproportionate number of assaults, but there is no clear pattern to the assaults. They are most likely due to an interaction of environmental and internal factors rather than to patient pathology. Since 1980, a 1-week staff training course has been provided to help staff reduce and address patient assaults. The part of the course dealing with security discusses various security levels (maximum, medium, and minimum). A discussion of interpersonal control focuses on how techniques of interaction with patients can assist in patients' development of self-control. The course addresses what can be done by staff daily to prevent patients from becoming agitated. The course discusses defusing techniques and uses videotapes to illustrate good and bad ways of interacting with patients. The final section of the course involves simulations and role play. Course evaluation shows a drop in the number of assaults and the number of staff days lost.