Objective: Impulsive traits are key characteristics in a number of psychiatric disorders and are part of the normal behavior spectrum. The BIS-5 is an instrument developed to assess impulsivity. The aim of this study is to evaluate the BIS-5 in two German psychiatric inpatient samples and healthy controls proving the originally proposed four-factor structure as well as convergent and discriminate validity.
Methods: 159 alcohol-dependent subjects and 77 suicidal inpatients were recruited in an University psychiatric hospital. 182 healthy subjects were recruited from town community. BIS-5 items were translated and back-translated. Principal component analysis with oblique rotation was conducted in the whole group. Furthermore, the discriminate and convergent validity of the BIS-5 was evaluated by correlation with other instruments measuring impulsive traits and comparing sample subgroups.
Results: A two-factor solution could be identified in this German sample. Alcohol-dependent individuals showed significantly higher factor 1 values compared to suicidal patients. The group of suicidal patients had higher scores in factor 2 compared to controls. Factor 1 correlated most significantly with extraversion-related personality traits while factor 2 showed significant relationships with irritability and neuroticism.
Conclusions: A two-factor solution may be more appropriate in using the BIS-5 scale in German samples. These two factors might reflect different aspects of impulsive behavior and might be useful to characterize impulsive behavior in psychiatric and non-psychiatric samples.