Ž . Psychiatry Research 71 1997 8395 Measurement of aggression in psychiatric patients Doron Gothelf a,b,  , Alan Apter a,b , Herman M. van Praag c a Geha Psychiatric Hospital, Petah Tiqwa, Israel b Sackler School of Medicine, Tel A®i ® Uni ®ersity, Tel A®i ®, I srael c European GraduateSchool on Neurosciencesand Brain and Beha®iour, Department of Psychiatry and Neuropsychology, Maastricht Uni ®ersity, P.O. Box 616, 6200 MD Maastricht, The Netherlands Received 3 August 1996; revised 20 March 1997; accepted 29 April 1997 Abstract This article analyzes, describes, and characterizes the methods used for measuring aggression in studies on psychiatric patients. The authors reviewed all studies published between 1985 and 1994 in seven major psychiatric journals and found 103 studies on adult aggression and 43 on childhood and adolescent aggression. Almost half Ž . 44.7% of the adult studies and 23.3% of the child and adolescent studies did not use any structured instrument; the remainder used a total of 52 different instruments, indicating that the methodology in this area is not well established. The methods used for measuring aggression were mainly of three types: observational measures; self-report questionnaires; and structured chart reviews. Each of these tools is described herein, with special focus on reliability and validity. Overall the reliability of the various scales is high, but the empirical validity is rather poor. In choosing a suitable method for measuring aggression, researchers should take into account the direction of Ž . investigation e.g. state vs. trait aggression, dynamic or biological aspects of aggression and the target population. Practical suggestions in this regard are offered.  1997 Elsevier Science Ireland Ltd. Keywords: Violence; Hostility; Anger; Measures; Tools 1. Introduction Ž . Bandura 1973 in his comprehensive work noted that the study of aggression is like ‘entering  Corresponding author. Geha Psychiatric Hospital, P.O. Box 102, 49100 Petah Tiqwa, Israel. Fax: q972 3 9241041; e-mail: nbrand@ccsg.tau.ac.il Ž . a semantic jungle’. Buss 1961 defined aggression as ‘a response that delivers noxious stimuli to another organism’, while other authors have in- Ž cluded self-aggression, vandalism Yudofsky et al., . 1986 and even intent in their definitions. Terms such as aggression and violence are used to describe destructive behavior, angry feelings, hostile fantasies and indirect attacks on objects. Ž . Buss 1961 argued that hostility, which he de- 0165-1781r97r$17.00  1997 Elsevier Science Ireland Ltd. All rights reserved. Ž . PII S0165-1781 97 00047-4