medwireNews: The risk for violence after the release of prisoners with sexual or violent offences is increased if they have untreated psychosis, a study shows.
Overall, there was no difference in the risk for violence between 742 former prisoners with no psychosis, 94 with schizophrenia, 102 with drug-induced psychosis, and 29 with delusional disorder, after accounting for drug and alcohol dependence.
However, when stratified by treatment, prisoners with untreated schizophrenia were a significant 3.43 times more likely than those without psychosis to commit a violent reoffence. Those who received treatment, whether in prison only or continuing after release, were no more likely to reoffend, and neither were prisoners with drug-induced psychosis or delusional disorders, irrespective of treatment.
These results confirm the prevailing opinion among clinicians that treatment of psychosis is critical for preventing violence, say lead researcher Robert Keers (Queen Mary University of London, UK) and colleagues.
“They also indicate that the inconsistent findings reported thus far in studies of psychosis and recidivism may, in part, be explained by the moderating effects of treatment,” they write in The American Journal of Psychiatry.
The team says that lack or refusal of treatment should therefore be included in instruments assessing violence risk in patients with psychosis.
The findings also show that the risk for violence is associated specifically with the development of persecutory delusions; prisoners experiencing these symptoms at follow-up (average 39.2 weeks) were a significant 3.42 times more likely to have reoffended during this time, relative to those without psychotic symptoms.
Persecutory delusions accounted for about 26% of the effect of untreated psychosis on the risk for violent reoffending. But other psychosis symptoms – hallucinations, thought insertion, or strange experiences – did not increase the likelihood that the patients would become violent.
The team says that more attention is needed to the identification and treatment of psychosis in prisoners. “Growing evidence suggests a complex association between delusions and violence, and our findings demonstrate that failure to treat schizophrenia results in the emergence of persecutory delusions and violence among released prisoners.”
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Eleanor McDermid, Senior medwireNews Reporter