"Aggressive behavior and impulsivity are often found in paranoid schizophrenia and can occur during both acute and chronic phases of the illness. Impulsivity is defined as action without planning or reflection, and it seems to be related to a failure of behavioral filtering outside of consciousness.
Patients with schizophrenia may show dysfunctional impulsivity and impulsive aggression. Although the neurobiological aspects of aggression in patients with schizophrenia are still not well understood, impulsivity and aggression may correlate with frontal and temporal brain abnormalities.2 Psychotic symptoms, such as delusions and hallucinations, with subsequent suspiciousness and hostility, may result in aggressive behavior. Or, aggression may be impulsive and caused by an environmental frustrating event. Patients may be more aggressive and violent during acute episodes.3
Schizophrenic patients have less insight, experience greater thought disorder, and have poorer control of their aggressive impulses."
