Violence among mentally disordered offenders : risk and protective factors

Abstract

Background: Violence is one of the leading causes of unnatural deaths, and the consequences of violence for victims, victims families, offenders, and society at large involve extensive suffering and monetary costs. Improving strategies to prevent and reduce violence is of great importance, and refining techniques for risk assessments in forensic and correctional settings is assumed to be one way of doing so. The procedures currently used for risk assessment mainly focus unchangeable, static risk factors, and provide few directions as to what clinicians can do in order to decrease a client's risk by treatment and management.

The aim of this thesis was to improve understanding of the violence relapse process, to identify triggers and protective factors for violence among mentally disordered offenders, and to develop a structured model for the management of violence risk in forensic mental health after-care.

Methods: This thesis used both qualitative and quantitative research designs. To identify protective factors of violent behaviour we interviewed individuals, selected from a cohort of 401 violent offenders who had unexpectedly ended their criminal career (n=4; Paper I). Semistructured interviews were likewise conducted to explore the violence relapse process and communication of risk among offenders who had relapsed into criminal violence (n=14; Paper II). Content analysis was used for the exploration of data. In the quantitative studies, which aimed to identify triggers of violence among offenders, we used the case-crossover design, by which each subject serves as his or her own control. Structured interviews were performed with 133 violent offenders with respect to hypothesised triggers (Papers III and IV). Standard Mantel-Haenszel methods were used for the statistical analyses. To develop a structured model for the management of mentally disordered offenders, we gathered law, criminology, and mental health professionals with different educational backgrounds to elicit clinically relevant contextual and individual factors related to the individual outcome following forensic psychiatric hospitalisation (Paper V).

Results: Qualitative studies suggested that the desistance process among individuals with long criminal and violent careers was triggered by a shocking experience related to their criminal lifestyle and insight about the negative consequences to that lifestyle. Suggested protective factors were a strong relationship with family, social and geographical isolation, and the identification and avoidance of potential risk situations. Important risk factors in the relapse process were separations, drug problems, homelessness, and acute risk factors were lack of sleep, substance intoxication and conflicts. Some of these acute risk factors of violence were tested and confirmed in the quantitative case-crossover study. Acute suicidal ideation/ parasuicide and alcohol intoxication were among the most important triggering factors. Acute conflicts and being denied psychiatric care also increased the risk of criminal violence. In contrast, potential inhibitors of violence were regular doses of benzodiazepines and antidepressants. All but one of the mentally disordered offenders interviewed in the relapse study had, by their own account, communicated that there was a risk of acting violently. The communication patterns were directed towards professionals and acquaintances and were verbal and non-verbal. Finally, a structured model for management of violence risk in forensic psychiatric after-care called the SORM (Structured Outcome Assessment and Community Risk Monitoring) was developed.

Conclusions: This thesis points to several potentially fruitful research areas for the violence prevention field. Previously, communication of risk has only been addressed in clinical work with suicidal patients, even though this may be of substantial interest also in the field of violence prevention. Some triggering and protective factors of violence among mentally disordered offenders were identified in this thesis, but needs to be replicated in future studies. The case-crossover design, for the first time applied to study triggers of aggressive acts, may substantially advance research on acute risk factors of violence.