Neuropsychological and symptom predictors of aggression on the psychiatric inpatient service.

Neuropsychological assessment of executive dysfunction may identify psychiatric patients who may be at high risk for aggressive behavior because impairment of the prefrontal cortex has been indicated as a possible anatomical correlate of aggression. No consensus, however, has been reached on the extent that executive dysfunction contributes to the formation of psychopathology and to aggressive behavior in psychiatric inpatients. We hypothesized a mediating model wherein patients' executive-functioning deficits contribute to the formation of psychopathological symptoms, which then underlies aggressive behavior. To test this model, we examined the relationship between executive functioning, psychiatric symptomatology, and aggressive behavior in 85 psychiatric inpatients presenting over an acute hospital admission using structure equation modeling techniques. The results revealed that psychiatric inpatients' executive function impairment significantly predicted the formation of psychiatric symptomatology, which in turn significantly contributed to the manifestation of aggressive behavior. Executive dysfunction also directly predicted inpatient aggressive behavior. Combining the indirect and direct effects, 59% of our inpatient aggression measure factor variance was accounted for by our measures of executive dysfunction and clinical symptom severity. These findings suggest that neurocognitive deficits underlie both psychiatric symptom formation and aggression. Patients with executive dysfunction may not possess the behavioral inhibition skills needed to cope with the presence of symptoms and other stressful events that accompany acute psychosis and hospitalization that may result, consequently, in increased manifestations of aggressive behavior.