Longitudinal trajectories to violent crime

Work Package 1 in the PreVio project focuses on subgoals 1 and 2: Objective 1 - Investigate changes in violent crime over time according to legislative revisions to the penal code and the mental health care act. Objective 2 - Identify subgroups and developmental trajectories through the life course.

These subgoals are related to a) the occurrence of violent crime among individuals with severe mental disorders compared to the general population in Norway, b) the identification of subgroups, and c) changes over time in patterns of violence associated with mental disorders based on legislative reforms, namely the revisions of the Penal Code in 2002 and 2016, as well as the revision of the Mental Health Care Act in 2017.

The data sources for this work package include a nationwide registry linkage with information on severe mental disorders, violent crime, and socioeconomic factors (ForenPsych, N ≈ 9 million). In the study of subgroups and developmental patterns, key socioeconomic factors such as education, income, employment, living conditions, and minority status are concurrently examined regarding their impact on the associations between severe mental disorders and violent crime. A central feature of this approach is the focus on socioeconomic factors related to upbringing rather than in adulthood. With this approach, we avoid reverse causality, as both mental disorders and convictions for violent crime can lead to a decline in socioeconomic status.

Furthermore, reports from hospitals and police, despite the lack of updated national incidence figures, suggest that violence associated with severe mental disorders is increasing, which tends to attract media attention. This has resulted in an intense public discourse that could further stigmatize an already vulnerable population. Based on population-wide data, co-PI Martin Tesli and colleagues have recently shown that annual incidence rates for severe mental disorders, such as schizophrenia and bipolar disorder, have been relatively stable in Norway over the past decade (Public Health Report 2021). According to figures from Statistics Norway, rates of violent crime have also been stable over the past decade. If the reports from police and hospitals can be confirmed with national registry linkages, it suggests that the risk of violent acts has increased specifically among psychiatric patients in recent years. This, in addition to causing concern, may potentially be linked to factors within the healthcare system, such as a reduction in hospital beds, lack of coordination between health, correctional, and other societal services, or the legal reforms described above.

Through updated incidence rates, a detailed characterization of subgroups, and developmental trends over time, and environmental modifiers that we will identify in Work Package 1, policymakers will gain significant information and insight to design more effective and impactful intervention strategies.