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Some schizophrenia patients become less prone to violence
when taking medication, but those with a history of childhood
conduct problems continue to pose a higher risk even with
treatment, according to a new study by researchers at Duke
University Medical Center.

"This is the first large randomized controlled study to
compare the effectiveness of several commonly-prescribed
medications for schizophrenia on reducing community violence,"
said Jeffrey Swanson, professor in psychiatry and behavioral
sciences and the study's lead author. "Serious violent behavior
is not frequent among people with schizophrenia, but when it
does occur, the results can be costly and tragic."

A Decline in Violence

The study found that violence declined significantly when
patients took antipsychotic medications as prescribed, but only
among patients whose prior risk for violence could be linked to
psychotic symptoms.

The researchers identified a subgroup of schizophrenia
patients with a history of childhood conduct problems who were
more likely to be violent at the beginning of the study. Among
these patients, violence was not strongly related to psychotic
symptoms, and did not significantly decline with adherence to
prescribed antipsychotic medication during the six-month study
period.

The new results, which are from the National Institute of
Mental Health's Clinical Antipsychotic Trials of Intervention
Effectiveness (CATIE) study, are published in the July issue of
The British Journal of Psychiatry.

"In the past, we've not understood very well why a small
proportion of patients with schizophrenia become seriously
violent, while most do not -- and why medication seems to
prevent violent behavior in some and not others," said Marvin
Swartz, professor of psychiatry and coauthor of the study.
"These findings tell us that people with schizophrenia may
behave violently for reasons not directly related to their
mental illness. If that's the case, then treatment for
psychotic symptoms alone may not eliminate the risk of
violence."

Who Behaves Violently?

Researchers found that a number of factors contributed to
violent acts independently of the person's schizophrenia. In
addition to childhood conduct problems, the following were all
predictors of violent behavior:

• substance abuse
• being the victim of past violent acts
• povert
• living with others, rather than alone

Treatment

Medication is the primary course of schizophrenia treatment
to reduce symptoms and hopefully prevent violent acts. This
study found that newer antipsychotics are as effective as older
medications in reducing violence among people with
schizophrenia.

"Contrary to the expectations of many clinicians and some
research, this study found no benefit for newer medications
over an older medication in reducing the risk for violence over
the six-month study period," Swanson said. "In fact, one of the
newer medications, quetiapine, performed worse than the
first-generation drug perphenanize."

The CATIE study included 1,445 patients with schizophrenia
who were randomly assigned to treatment with one of five
antipsychotic medications, including olanzapine, perphenanize,
quetiapine, risperidone, or ziprasidone.

"Antipsychotic drugs may help reduce violence risk, but they
don't address all of the causes of violent behavior and they
don't help at all if people can't or won't take the medication
prescribed. We also need interventions to help patients stay
engaged in treatment," Swartz added.

The study's co-authors include Richard A. Van Dorn, Ph.D.,
Joseph P. McEvoy, M.D., and H. Ryan Wagner, Ph.D., of Duke
University Medical Center, Jan Volavka, M.D., Ph.D., of New
York University, John Monahan, Ph.D., of the University of
Virginia, T. Scott Stroup, M.D., M.P.H., and Eric B. Elbogen,
Ph.D., of University of North Carolina at Chapel Hill and
Jeffrey A. Lieberman, M.D., of Columbia University for the
CATIE Investigators.