RESUMO
INTRODUCTION: Aggression has been linked to several psychiatric disorders. None of the available instruments validated in Mexico is able to classify aggression as impulsive or premeditated. The Impulsive/Premeditated Aggression Scale (IPAS) is a self-report instrument designed to characterize aggressiveness as predominately impulsive or premeditated. OBJECTIVE: The aim of the study was to determine the validity and reliability of the IPAS in a sample of Mexican psychiatric patients. METHOD: A total of 163 patients diagnosed with affective, anxiety or psychotic disorder were included. A principal-component factor analysis was performed to obtain construct validity of the IPAS impulsive and premeditated aggression subscales; convergent validity as well as internal consistency of subscales were also determined. RESULTS: The rotated matrix accounted for 33.4% of the variance. Significant values were obtained for convergent validity and reliability of the IPAS subscales. CONCLUSION: The IPAS is an adequate instrument, which might be used to differentiate the type of aggressive behavior in Mexican psychiatric patients.
