Multivariable modelling of factors associated with criminal convictions among people experiencing homelessness and serious mental illness: a multi-year study

Homelessness, psychiatric disorders, and violence in Denmark: a population-based cohort study

BACKGROUND

Homelessness is associated with adverse health and social outcomes. People experiencing homelessness have been found to have a high risk of violent crime victimisation as well as high prevalence of psychiatric disorders. It is poorly understood whether experiencing homelessness is associated with additional risks of violent offending and whether psychiatric disorders contribute to these risks. We examined the association between homelessness, psychiatric disorders, and first violence offence leading to conviction.

METHODS

We did a nationwide, register-based cohort study of all Danish residents who were alive at least 1 day during the study period, born between Jan 1, 1980, and Dec 31, 2006, and aged 15 years or older retrieved from the Danish Civil Registration System, which was linked to registers with information on homelessness, health care, and criminality. The exposure was any experience of homelessness, which was defined as having at least one contact with a homeless shelter during the study period. The outcome was first violent offence leading to a conviction. We calculated incidence rates per 10 000 person-years, incidence rate ratios (IRRs) using Poisson regression analysis, and probability of conviction of a violent offence using an Aalen-Johansen estimator. Analyses were stratified by sex and adjusted for calendar year of the study period, age, other sociodemographic factors, and psychiatric disorders.

FINDINGS

The study cohort included 1 786 433 Danish residents aged 15-42 years living in Denmark at some point from Jan 1, 2001, to Dec 31, 2021, contributing to 21 336 322 person-years at risk, of whom 57 084 (3·2%) individuals had their first violent offence leading to conviction during follow-up. 10 years after their first contact with a homeless shelter, 22·9% (95% CI 21·6-24·2) of men and 7·7% (6·8-8·7) of women had committed at least one violent crime leading to conviction. The fully adjusted IRRs of a violent offence leading to conviction were 4·8 (4·5-5·1) in men and 6·3 (5·6-7·2) in women experiencing homelessness compared with individuals who had not experienced homelessness. The IRR for a violent offence leading to conviction was highest in individuals experiencing homelessness and having co-occurring psychiatric disorders compared with those not experiencing homelessness and without co-occurring psychiatric disorders, especially drug use disorders (IRR in those experiencing homelessness and having a drug use disorder: 15·3 [14·1-16·7] in men and 40·1 [33·9-47·5] in women compared with individuals not experiencing homelessness and having no drug use disorder).

INTERPRETATION

Individuals experiencing homelessness had higher risks of a violent offence leading to conviction than those who had not experienced homelessness. In addition to preventing homelessness, public health and policy should consider how to reduce the risk of adverse outcomes in people experiencing homelessness.

FUNDING

Lundbeck Foundation.

The Relationship Between Serious Mental Illness and Criminal Offending in Persons Experiencing Homelessness: The Role of Substance Use Disorder

Individuals who live with mental illness are encumbered by related risk factors that increase the probability of legal involvement. The goal was to determine how homelessness and substance use disorder are intervening factors in the relationship between symptoms of serious mental illness (SMI) and criminal offending. A sample of 210 chronically homeless adults receiving SAMHSA-funded outreach and psychiatric rehabilitation services between 2014 and 2016 was recruited in a study of interventions to address housing in homeless persons with a SMI. Participants were interviewed and data collected were analyzed using structural equation modeling. Statistical analysis showed that homelessness severity mediated the relationship between SMI symptom severity and criminal offenses committed in the past 30 days in participants with a substance use disorder but not in those with no substance use diagnosis. Results show that homelessness and substance use are important to address to possibly alter trajectories for criminal justice involvement.

Serious Mental Illness Exacerbation Post-Bereavement: A Population-Based Study of Partners and Adult Children

Purpose

The death of a close family member is commonly accompanied by intense grief, stress, and loss of social support. We hypothesized that recent bereavement would be associated with an increase in symptom exacerbations among adults with serious mental illness (SMI) whose partners or parents had died.

Patients and Methods

Adults whose partners and parents had died in Denmark between January 1, 2010, and June 30, 2016, were identified using linked population-based registries. History of SMI was defined as having a diagnosis of schizophrenia and schizoaffective disorders, major depression, and bipolar disorder in the five years preceding their family member's death in the Danish Psychiatric Central Research Register using International Classification of Diseases-10 codes. The odds of SMI exacerbation (ie, attempt or completion of suicide or psychiatric hospitalization) among partners and children in the first two years after death in 3-month intervals were estimated with generalized estimating equations.

Results

12.8% of partners and 15.0% of adult children with a history of SMI experienced any SMI exacerbation two years after bereavement. Among bereaved partners, older age (80+ years) was associated with a lower risk of experiencing an SMI exacerbation compared with partners aged 18-49 years (ORadj=0.29, [0.18-0.45]). Partners with a history of SMI had significantly increased odds of SMI exacerbations three months after their partners' death compared to prior to their partners' death (ORadj = 1.43, [1.13-1.81]). There was no evidence that adult children with SMI experience increased SMI exacerbations after the death of their parents compared to prior to death.

Conclusion

Adults with a history of SMI whose partners had died are at increased risk for an SMI exacerbation post bereavement. Additional bereavement resources and support should be provided to those with a history of SMI, especially in the period immediately after death.