Signals of impending violence.

Swift swings in symptom intensity may peg psychiatric patients on the verge of threatening or hurting others.

Employing a statistical technique, new work shows that among psychiatric patients with documented histories of committing violent acts, those whose symptoms of emotional distress rapidly and repeatedly fluctuated from mild to severe during a 26-week period were particularly apt to assault others or to threaten them with a weapon, say Candice Odgers of the University of California, Irvine and her colleagues.

In cases of rapid symptom fluctuation, patients went from peaks to valleys of emotional health about every two to four weeks, the team reports in a paper published online April 15 and in the May American Journal of Psychiatry.