it is still not clear what the unique contribution of particular psychopathological factors is in explaining
aggression in schizophrenia. The current study examined whether persecutory ideations, psychopathy
and substance use are associated with different measures of aggressive behavior. We expected that
persecutory ideations are associated with reactive aggression, and psychopathic traits are more asso-ciated with proactive aggression of inpatients. 59 inpatients with schizophrenia were included. Persec-utory ideations we assessed using the Persecutory Ideation Questionnaire (PIQ), psychopathic traits with
the revised version of Psychopathic Personality Inventory (PPI-R) and substance use was assessed using
the Comprehensive Assessment of Symptoms and History (CASH). In addition, aggression was measured
with the Reactive and Proactive Aggression Questionnaire (RPQ), in an experimental task using the Point
Subtraction Aggression Paradigm (PSAP) and on the ward using the Social Dysfunction and Aggression
Scale (SDAS). Results showed that psychopathy explains most of the variance in self-reported proactive
and reactive aggression. In contrast, persecutory ideations explain most of the variance in observed
aggression on the ward. Results implicate that it is important to acknowledge comorbid factors in pa-tients with schizophrenia for more precise risk assessment and appropriate treatment for aggressive
patients with schizophrenia