medwireNews: People are at particular risk for violent behavior during a first episode of psychosis if they have displayed antisocial behavior since childhood, show findings from the UK National EDEN Study.
The study authors identified four distinct types of premorbid delinquency and, of these, stable high delinquency was associated with the greatest risk for violent behavior and was the only type to have a direct effect.
“The continuance of antisocial tendencies may have accounted for the increased risk for violent behavior in this group,” suggest Swaran Singh (University of Warwick, UK) and colleagues.
They add: “Early intervention strategies should target antisocial traits, and treatment approaches should focus simultaneously on the psychotic disorder and violent behavior.”
The four types of premorbid delinquency identified in 670 first-episode psychosis patients were stable (starting in childhood) low delinquency (48.5%), stable moderate delinquency (28.7%), stable high delinquency (13.2%), and early adolescent-onset high-to-moderate delinquency (9.7%).
Six months after starting early intervention, 8.6% of patients showed violent behavior, and at 12 months the rate was 8.5%.
The patients with stable high delinquency were 3.5 times more likely to report violence than were those with stable low delinquency. The risk was increased twofold for patients with stable moderate delinquency.
The delinquency classes were significantly associated with other psychotic risk factors, such as past drug use, longer duration of untreated psychosis, higher positive symptom scores, and younger age at illness onset.
Stable moderate delinquency indirectly predicted violent behavior via positive symptoms, but stable high premorbid delinquency was the only independent risk factor, along with positive symptoms and younger age at illness onset, the researchers report in JAMA Psychiatry.
“Moderate premorbid delinquency may represent a general risk marker for poorer outcome rather than a specific risk marker for violent behavior,” they suggest.
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013