Understanding and Preventing Violence, Volume 2: Biobehavioral Influences (1994)
Chapter: Schizophrenia
of emotion provided the impetus and rationale for a considerable body of research attempting to discover disturbed brain function in persons with neuropsychiatric disorders, especially disorders of emotion. Structures comprising the limbic system (amygdala, hippocampus, cingulate gyrus, portions of the thalamus and hypothalamus, and their connections) have been special targets of this research (Figure 1). However, the limbic system is ordinarily difficult to observe, measure, or study directly (except in certain neurosurgical cases); therefore, most studies of neuropsychiatric patients have attempted to measure brain abnormalities as best they could by examining electroencephalogram (EEG) records or searching for ''soft" or hard neurologic signs, such as the presence of seizures. The advent of newer, sophisticated, and relatively noninvasive imaging techniques such as computerized tomography (CT) scans, regional cerebral blood flow, magnetic resonance imaging, and positron emission tomography (PET) has made the study of limbic and limbic-related structures in humans more feasible. Some imaging research with neuropsychiatric patients exhibiting violent behavior has been done and is reviewed later in this paper.
Schizophrenia
Although there may be a connection in the view of lay persons between the co-occurrence of major psychiatric disorders such as schizophrenia and violent behavior, the evidence is in fact not very compelling. We report here six recent investigations involving schizophrenia.
There are a few reports of increased aggressiveness or assaultiveness in patients with the diagnosis of schizophrenia (Tardiff and Sweillam, 1980; Krakowski et al., 1986; Karson and Bigelow, 1987) (Table 3).* Tardiff and Sweillam (1980) attribute the violence to either the sex (male) or the socioeconomic status of the patient (low). Krakowski et al. (1986) focus on the role of violence in the disorder of the patient and remind us that the carrying out of assaults is incompatible with the disorganized psychotic states seen in severe psychiatric illness. Karson and Bigelow (1987) report an increased incidence of assaultive behavior in schizophrenic patients in comparison with those carrying other diagnoses. However, the assaultive patients were also younger and tended to have a prior history of violence.
Robertson (1988) makes much the same point as Krakowski et
