Violent offending severity among injecting drug users: Examining risk factors and issues around classification

•There is currently no way to uniformly classify the severity of violent behaviour.•Four severity classification schemes were tested among injecting drug users (IDU).•Severely violent IDU differed significantly in risk profile from lower level IDU.•Higher cumulative risk exposure was associated with more severe violent offending.•There was considerable lack of uniformity in correlates of severe violent offending.

ObjectiveThere is a paucity of research as to how injecting drug users (IDU) might be differentiated in the severity of their violent offending. This paper reported on the risks associated with severity, as well as issues around severity classification and the impact on observed relationships with known major risk factors.MethodA cross-sectional survey administered to 300 IDU, who had injected drugs weekly or more in the past 12 months. A structured questionnaire addresses potential substance use and early-life risk factors for violent offending.ResultsFour severity groups were identified: non-violent (24%), low (34%), moderate (22%) and high (20%) level offenders. Higher severity groups had more prevalent and more severe histories of childhood maltreatment, child psychopathology and dysfunctional trait personalities, as well as more severe substance use problems than low-level and non-violent IDU. Regression analyses found that only two of 15 risk factors remained uniformly associated with violent offending across the four classification schemes tested: (1) having committed violence under the influence and (2) having more impulsive trait personalities.ConclusionsDisaggregating IDU into distinct subgroups showed that the extent and severity of predispositional and substance use risk exposure corresponded to the severity of violent offending. There is a need to establish a systematic method for classifying severity given that there were clinically meaningful differences between groups which require further exploration and replication, and because there was extensive variation in the risks associated with severity across schemes.