Increased prevalence of psychopathy and childhood trauma in homicide offenders with schizophrenia compared to nonviolent individuals with schizophrenia

Abstract

Purpose: Schizophrenia is associated with an increased homicide risk. Personality pathology, particularly antisocial personality disorder and psychopathic traits, has been associated with increased violence risk in schizophrenia. Childhood trauma, more specifically physical abuse, has been associated with violence risk in healthy populations and in individuals with mental illness. It is, however, unclear how childhood trauma relates to homicide in schizophrenia. This is, to our knowledge, the first study to concurrently examine personality pathology and childhood trauma in a group consisting solely of homicide offenders with schizophrenia (HOS). HOS is compared to nonviolent participants with the same diagnosis (non-HOS). Additionally, currently assessed demographical and clinical characteristics of a Norwegian sample of HOS are reported.

Materials and methods: Two groups of participants with schizophrenia were recruited in collaboration with in and outpatient clinics across Norway, HOS (n= 26) and non-HOS (n= 28). Assessments of personality pathology and childhood trauma were conducted, and information about clinical and demographical characteristics was registered.

Results: HOS participants had significantly higher psychopathy scores, and more frequently reported moderate to severe childhood physical abuse than non-HOS participants. When simultaneously added to a logistic regression model, only psychopathy uniquely contributed to explaining group membership.

Conclusions: Psychopathy and physical abuse was more prevalent among HOS participants compared to non-HOS, but only psychopathy independently predicted homicidal status. These results confirm the importance of including an evaluation of psychopathic traits in violence risk assessments of individuals with schizophrenia.

Keywords:

• Violence
• PCL: SV
• CTQ
• personality pathology
• physical abuse

Acknowledgements

The authors would like to thank the participants and collaborating units for their efforts.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Katharina Nymo Engelstad

Katharina Nymo Engelstad: Research Department, Vestre Viken Hospital Trust, Drammen, Norway

Bjørn Rishovd Rund

Bjørn Rishovd Rund: Research Department, Vestre Viken Hospital Trust, Drammen, Norway, and Department of Psychology, University of Oslo, Oslo, Norway

Bjørn Lau

Bjørn Lau: Department of Psychology, University of Oslo, Oslo, Norway, and Department of Research, Lovisenberg Hospital, Oslo, Norway

Anja Vaskinn

Anja Vaskinn: Norwegian Centre for Mental Disorders Research (NORMENT), Oslo University Hospital, Oslo, Norway, and Institute of Clinical Medicine, University of Oslo, Oslo, Norway

Anne-Kari Torgalsbøen

Anne-Kari Torgalsbøen: Department of Psychology, University of Oslo, Oslo, Norway