Introduction

Institutional violence and associated risk factors within state hospitals have largely remained unexamined in the literature in spite of high violence prevalence rates: almost one-third (31.4%) of state hospital inpatients will engage in a violent assault during their hospitalization course.¹ This dearth of research is particularly true for state hospital inpatients adjudicated not guilty by reason of insanity (NGRI). An NGRI status indicates that an individual has been evaluated and deemed guilty of a criminal act but, due to mental disease or defect, was incapable of either knowing or understanding the nature of their act or was incapable of distinguishing between right and wrong at the time of their crime.² Unfortunately, the majority of research examining violence and associated risk factors has been conducted among state hospital inpatients upon release into the community.^3,4 Such research provides little insight into violence that occurs within the walls of the hospital and jeopardizes the safety of the patients and staff. Existing research also has not focused specifically on NGRI inpatients, but rather state hospital inpatients broadly. This is problematic because preliminary research demonstrated that the rates of violence toward other patients and staff were higher among NGRI inpatients than patients committed as incompetent to stand trial.¹ To further expand this scant literature, the current study aimed to evaluate both psychiatric symptoms and criminogenic risk (i.e. risk factors that, when present, increase an individual’s risk of engaging in criminal activity and/or violence) as they relate to institutional violence over time during NGRI inpatients’ hospitalization.

Narrow research has been conducted on psychiatric symptoms and criminogenic risk factors that may contribute to institutional violence risk among NGRI inpatients. Particularly concerning is that research examining violence among NGRI inpatients⁵ has largely focused on psychiatric symptoms while neglecting criminogenic risk factors.^6,7 Given that an NGRI commitment status indicates a nexus between criminal behavior and mental illness, research examining traditional criminal risk factors for violence, in conjunction with psychiatric symptoms, may elucidate important treatment targets for NGRI inpatients and enhance institutional safety.

The relationship between severe mental illness and violence is complex.⁸ A recent meta-analysis indicated that approximately one in five community psychiatric inpatients engaged in violent behavior during their hospitalization.⁹ This study also found that among other factors (e.g. being male, history of violence, and alcohol abuse diagnosis), schizophrenia was linked to institutional violence.⁹ Similarly, in another sample of community psychiatric inpatients, schizophrenia was associated with increased risk of institutional assault.¹⁰ Furthermore, in a forensic state hospital sample, 82% of which were NGRI inpatients, both impulsivity and psychiatric symptoms, as measured by the Brief Psychiatric Rating Scale, were associated with greater violence.⁵ Moreover, based on a literature review and synthesis of qualitative features of violent prisoners, those with a severe mental illness diagnosis (schizophrenia or other psychotic disorder, bipolar disorder, or major depression) and active psychiatric symptoms (psychotic symptoms, confusion, or depression) were more likely to engage in institutional violence than those without these characteristics.¹¹ Taken together, this research suggests a link between severe mental illness and violence risk among psychiatric inpatients and individuals who are criminally engaged. However, these studies did not take another body of literature into consideration when examining violence – namely the role of criminogenic risk factors. It was long assumed that criminal justice involvement for individuals with mental illness was due to untreated mental illness;¹² however, in the past 15 years, it has been recognized that criminogenic risk significantly contributes to criminal justice involvement to a greater degree than does psychopathology.^13,14

Research has identified eight central criminogenic risk factors including: antisocial personality, antisocial attitudes, antisocial peers, substance abuse, history of antisocial behavior, relationship/familial problems, vocational difficulties, and lack of leisure activities.¹⁵ There is concordance between these criminogenic risk factors and factors that have been associated with institutional violence within forensic settings. For example, a recent meta-analysis examined individual factors that differentiate violent versus nonviolent psychiatric inpatients across a variety of inpatient settings, including a community acute psychiatric hospital, a forensic hospital, and veterans inpatient psychiatric units.¹⁶ This study found multiple risk factors that increased probability of violence, two of which could be considered related to criminogenic risk factors: a history of violence and a history of substance abuse.¹⁶ Additionally, a diagnosis of schizophrenia was most strongly associated with increased inpatient violence compared to all other diagnoses. Other studies have indicated that antisocial behavior, criminality, and impulsivity were associated with institutional violence in forensic psychiatric hospitals and correctional settings.^17,18 In sum, these studies indicate that independently, psychiatric symptoms and criminogenic risk factors may be important predictors for violence among individuals with psychiatric symptoms and criminal justice involvement. As such, these factors may also confer greater risk for violent behavior among NGRI inpatients, which is the focus of the current study.

Given the multifaceted relation between mental illness, criminogenic risk, and violence, the current study sought to provide clarity on this topic in a sample of NGRI state hospital inpatients – a high-risk and understudied group. Because NGRI patients are at the crossroads of mental illness and criminality, the current study examined associations between psychiatric symptoms, criminal risk factors, and future institutional violence. As an exploratory aim, we provided updated rates of violence among NGRI inpatients, as well as descriptions of patient characteristics. First, we hypothesized that NGRI inpatients who engaged in institutional violence during the six-month follow-up period would report more severe psychiatric symptoms at the time of assessment compared to NGRI inpatients who did not engage in institutional violence during the follow-up period when controlling for previous violence. Second, we hypothesized that NGRI patients who engaged in institutional violence during the six-month follow-up period would report higher criminogenic risk at the time of assessment than people who did not engage in institutional violence during the follow-up period when controlling for previous violence.