Predicting violence in schizophrenic and non-schizophrenic patients: A prospective study

Abstract

This study examined predictors of violence in schizophrenic and nonschizophrenic mental health patients. Data were obtained for a sample of 304 adult male patients who were admitted for short‐term emergency treatment and consisted of mental hospital admission records, arrest records, and interview data on demographic, early history, and current situational variables. Subjects were classified as violent or non‐violent during a 1‐year follow‐up period based on arrest and readmission records. The sample was divided into schizophrenic and non‐schizophrenic groups, and a discriminant analysis was conducted for each group using intake data as independent variables to predict violent recidivism. The results indicated some patterns of different predictors for the two groups. Life events, substance abuse, and self‐reported arrests for violent crime were predictive of subsequent violence for non‐schizophrenic patients but not for schizophrenic patients. Selfreported incidents of violence other than arrests predicted subsequent violence for schizophrenic but not for non‐schizophrenic patients. Classification results for both groups were excellent, with 88.1% and 92.9% correct classification and 17.6% and 9.4% false positive rates for schizophrenic and non‐schizophrenic patients, respectively.

A review of arrests among psychiatric patients

“…Younger patients were found in four studies to be more likely to be arrested or to exhibit arrestable behaviors (Harry & Steadman, 1988;Holcomb & Ahr, 1988;Klassen & O'Connor, 1988;Steadman et al, 1984). Younger age is only a factor in increased arrest rates when arrests are considered within a specific, limited time frame.…”

“…Other researchers did not derive a standardized percentage of patients arrested, so comparisons with the McFarland et al result are impossible. Klassen and O'Connor (1988,1988a, 1988b) used a sample composed of men who were predisposed to violence, which explains why 74% of their sample had been arrested. The percentage of schizophrenics in the sample with arrest records (76%) was similar.…”

“…The corresponding result for the schizophrenics in the sample was somewhat lower (15.6%). Klassen and O'Connor (1988) reported that 39% of their violently predisposed schizophrenics and 41% of the entire sample had been arrested previously for a violent crime. Presumably, the percentages of schizophrenics and psychiatric patients in general with prior arrests for violent crime would be lower for other populations than those reported for these two "skewed" samples.…”

“…These four variables accounted for 25070 of the variance. Klassen and O'Connor (1988, 1988a, 1988b published three reports which identified predictors of violence in a mentally ill population. Their sample was composed of 304 men predisposed to violent behavior.…”

“…Schizophrenics had the following mean numbers of arrests and readmissions during the study time frame of 1 year: inpatient readmissions, 1.14; arrests, 1 .OS; arrest for violent crime, 0.16; readmissions for violence, 0.31; and total of arrests and readmissions for violence, 0.47. Klassen and O'Connor (1988) used the same sample to study predictors of violence in 236 schizophrenic and nonschizophrenic patients. The study period was 1 year after release from the CMHC.…”