Patient characteristics associated with aggression in mental health units.

Aggression in mental health units is a significant and pervasive problem. However, the characteristics of patients associated with increased aggression propensity remain unclear and there are few attempts to expand understanding of these characteristics by drawing upon contemporary aggression theory. This study assessed the influence of interpersonal (hostile-dominance) and personality (psychopathy), General Aggression Model-specified (aggressive script rehearsal, attitudes towards violence, and trait anger), and clinical (psychiatric symptoms) factors on aggression during psychiatric hospitalization in 200 inpatients (132 men and 68 women; 19-64 years, M=38.32 years, S.D.=11.13 years). Patient characteristics were assessed on admission using structured interviews and self-report psychological tests. Patients' files were reviewed and nurses were interviewed after patients were discharged to establish whether patients were aggressive during their hospital stay. Results of univariate analyses showed that higher levels of interpersonal hostile-dominance, psychopathy and aggressive script rehearsal, positive attitudes towards violence, trait anger, and disorganized and excited type psychiatric symptoms all predicted aggression. In the final multivariable logistic regression model, only hostile-dominance remained as a significant predictor of aggressive behavior. This important personality characteristic should be considered in violence risk assessments and aggression prevention strategies.