The development of an observer-scale for measuring social dysfunction and aggression.

Scales for measuring aggressive cognitions and behaviour have mainly been administered by nursing-staff or been self-ratings. During recent years we have made an attempt to construct an observer-scale for aggression analogous to the Hamilton scale for depression. The Social Dysfunction and Aggression Scale (SDAS) consists of 9 items (SDAS-9) covering outward aggression and 2 items (SDAS-2) covering inward aggression. The inter-observer reliability of the SDAS has been found adequate in terms of intra-class coefficients. In a pilot study on 82 inpatients from different centres in Denmark and Sweden the SDAS was compared to three-item scales for outward and inward aggression and to a global scale for outward aggression. The results showed that the SDAS-9 correlated positively with the other outward observer-scales, and the SDAS-2 with the other inward scale. A divergent validity was seen between the outward and inward scales, indicating that it is necessary to measure both dimensions. Preliminary ranks-according-to-frequency scores showed the following order of the nine outward items: irritability, dysphoric mood, social disturbances, nondirected verbal aggressiveness, negativism, directed verbal aggressiveness, physical violence towards staff, physical violence towards things, and physical violence towards persons other than staff.