Antisocial Behavior Raises Violence Risk in Some Psychosis Patients

The first episode of psychosis may represent a period of heightened risk for violence, recent studies have suggested. Yet determining which individuals are at risk for such violence is difficult.

Now some guidance has emerged from a prospective study published online October 2 in JAMA Psychiatry. Patients who have been engaging in antisocial behavior for some time before experiencing a first episode of psychosis may be especially in jeopardy of engaging in violence after the episode.

Heading the study was Swaran Singh, M.D., a psychiatrist and head of the Division of Mental Health and Wellbeing at the University of Warwick Medical School in England.

The study included 670 young adults being treated at five treatment locations in England for a first episode of psychosis. They were evaluated at baseline with a self-report instrument called the PAS School Adaptation Scale to assess whether they had engaged in antisocial behavior during childhood, early adolescence, or late adolescence.

Examples of antisocial behavior were truancy, vandalism, or disciplinary problems. Forty-nine percent of the subjects were found to have engaged in stable low levels of antisocial behavior, 29 percent in stable moderate levels of antisocial behavior, 13 percent in stable high levels of antisocial behavior, and 10 percent in early-adolescent-onset high-to-moderate levels of antisocial behavior.

At six months and 12 months after the study began, the subjects were evaluated with the Adverse Outcomes Screening Questionnaire to determine whether they had engaged in any violent behavior during the previous six months. Physically harming another person was considered violent behavior; 14 percent of the cohort were violent at the six- or 12- month follow-up.

Finally, the researchers assessed whether the subjects’ antisocial behavior histories had a bearing on whether they engaged in violence during the six months or one year following their psychotic episode.

Nine percent of the group with stable low levels of antisocial behavior, as well as 9 percent of the early-adolescent-onset high-to-moderate levels of antisocial behavior group, engaged in violence. In contrast, 16 percent of the group with stable moderate levels of antisocial behavior and 25 percent of the group with stable high levels of antisocial behavior engaged in violence. Compared with the stable low-level group, the stable moderate group was twice as likely to commit violence, and the stable high group was four times as likely to commit violence.

There are two key implications of these findings, Singh told Psychiatric News. “First, management of psychosis in some individuals must also target the risk of aggression. Secondly, if the risk of aggression in this subgroup is driven by underlying personality traits rather than the overlying psychotic illness, legal issues such as ‘diminished responsibility’ should be carefully considered rather than simply assumed.”

“The findings from this study of first-episode schizophrenia patients in England indicate continuity of antisocial behavior pre- and post-onset of illness,” forensic psychiatrist Paul Appelbaum, M.D., said in an interview. “People who were more likely to offend before they manifested symptoms of schizophrenia were also more likely to be violent afterward.” A former APA president, Appelbaum is the Dollard Professor of Psychiatry, Medicine, and Law at Columbia University and chair of the APA Committee on Judicial Action.

“These data have implications for violence prediction and treatment in patients with schizophrenia,” Appelbaum continued. “From a prediction perspective, first-episode patients with a long history of juvenile offenses constitute a higher-risk group for violence after illness onset. A quarter of this group reported committing violence, even though they were in ongoing contact with treatment services. In addition, from a treatment perspective, these data suggest that treatment targeting psychotic symptoms in higher-risk patients may not be enough to prevent violent behavior—interventions aimed specifically at propensities for violence may be needed as well.”

Also commenting on the study for Psychiatric News was Thomas McGlashan, M.D., a professor of psychiatry at Yale University and an expert on the prodromal phase of schizophrenia.

“Simply put,” he said, “these data point out that youth with a history of delinquent behaviors and a vulnerability for psychosis are clearly at risk for behaving violently once that vulnerability becomes expressed as a first episode of schizophrenia. For this subsample of young people,” he said, “early detection and intervention at the pre-onset or prodromal phase of the disorder may be doubly protective by preventing not only the onset of psychosis, but also the perpetration of any associated expression/magnification of antisocial behaviors. It is hard enough for a young person to deal with either problem. Dealing with both is much more likely to be overwhelming and to result in a poor long-term outcome.”

The research was funded by the United Kingdom Department of Health. ■