Violence has been described since ancient times in various writings and in different forms (armed conflicts; physical abuse on women, children or the elderly; neglect or psychological constraints). Its impact is significant and can be seen in all parts of the world.
Violence can be defined in several ways, but a comprehensive definition is that of the World Health Organization (WHO): “the intentional use of physical force or power, threatened or actual, against oneself, another person, or against a group or community, that either results in or has a high likelihood of resulting in injury, death, psychological harm, maldevelopment, or deprivation”(1).
It has been estimated that tens of thousands of people are victims of violence every day(2). In addition, 2.5% of all worldwide deaths are attributed to violence(3) and 1.4% are attributed to suicide(4).
Exposure to violence has serious consequences on the physical and mental health status, but also on a person’s behavior. It increases the risk of substance abuse and dependence (smoking, alcohol and drugs), of chronic somatic disease (diabetes, cardiovascular and infectious disease), and of mental disorders (anxiety, depression, sleep and eating disorders)(2). Moreover, violence has a negative impact on society by the increase in criminality and the substantial burden imposed on families, communities and healthcare systems worldwide.
Violence in major psychiatric disorders
Psychiatric patients are often seen as having a violent behavior and a tendency toward criminality(5). In the case of those who commit crimes, the stigma associated with having a mental disorder is doubled by that resulting from the contact with the criminal justice system.
The Epidemiological Catchment Area(6) was one of the first studies that attested the correlation between mental disorders and violence. The study was conducted in five big cities in the United States of America and included a community sample of over 17,000 participants. It identified a lifetime prevalence of violence of 7.3% in people without documented mental disorders and 16.1% in persons with major psychiatric disorders (particularly affective disorders and schizophrenia). When harmful substance use was associated, the percentage increased to 35%, and for those with substance abuse, the lifetime prevalence for violence was 43.6%. The study suggests that, while major mental disorders appear to be associated with violence, a significant role in increasing the likelihood of committing acts of violence is attributed to substance abuse.
The conclusions of another study from the USA(7) showed that the prevalence of violence among patients diagnosed with a mental disorder and in those without a psychiatric diagnosis who lived in the same neighborhood was similar. In addition, the prevalence of violence among patients discharged from psychiatric hospitals varied with diagnosis. The research team monitored a group of 1136 patients aged between 18 and 40 years old over a period of one year after discharge from a psychiatric hospital and compared them to 519 controls. Substance abuse significantly increased the rate of violence in both groups.
Violence is associated with a wide range of psychiatric disorders that include psychotic disorders, major depression and bipolar affective disorder, personality disorders, dementia, posttraumatic stress disorders and conduct disorders(8).
Recent studies from the Czech Republic(9) and China(10) have shown that patients with major psychiatric disorders, mainly schizophrenia and other psychotic disorders, have an increased risk of violent offending. Furthermore, a younger age at the time of the first offence, a lower level of education, residence in the rural area and a diagnosis of schizophrenia were significantly and positively associated with homicide.
It is interesting to note that most of the conducted research focuses on violence in schizophrenia. As schizophrenia is not the only, nor the most prevalent of mental disorders(11), violence is neither the only or the most common offence committed by persons with mental health problems(12). Certainly, public opinion plays an important role here, as psychosis is difficult to explain and is accompanied by a sense of fear.
Regarding dementia, patients diagnosed with the frontotemporal type are more likely to exhibit criminal behavior than those diagnosed with Alzheimer’s disease(13). Also, the presence of psychotic symptoms and the association of alcohol abuse increase the risk for violence in this group of patients(14).
Bipolar disorder is often associated with personality disorders and substance abuse, and criminal offending is common among these patients, even during the periods of euthymia(15,16).
A significant body of research focuses on the predictors of psychiatric disorders and the relationship between them and criminal behavior.
Personal factors like age, male gender, ethnicity, celibacy, a low educational level and unemployment are associated with violent offending and recidivism(17-20).
Barlati et al. found that past violence is an important predictor for future aggressive behavior in terms of severity and frequency for outpatients with serious mental disorders(21).
Traumatic brain injury is highly prevalent among adult offenders compared to the general population and it appears to be associated with an increased risk for violence and reoffending(22).
Studies reporting on epilepsy and criminal behavior are scarce and heterogenous, and no clear relationship between the epileptic activity and violence was found(23).
Individuals who experience positive psychotic symptoms like delusions of persecution(24,25) and command hallucinations to harm others(26) are at a high risk to become violent. A significant association was found between a low level of insight, nonadherence to treatment and serious violent behavior(27-29). In addition, the importance of treatment in the management of aggression and agitation in mental disorders is increasingly emphasized(29,30).
Other incriminated factors are a personal history of childhood conduct disorder(31,32), a family history of violence(33) and parental drug abuse(18).
It has been assumed that the presence of a mental disorder in early adulthood predicts violent offending and that the association of a substance use disorder is one of the strongest predictors of crime for males in the general population(34). Binge drinking was found to be positively associated with violent crime and sedatives use with fatal violence(35).
The existence of a personality disorder (PD) increases the risk for violent behavior up to three times(36). Among offenders, those with a PD diagnosis are at higher risk for recidivism, although there are significant differences between the types of personality disorders(37). While nonviolent offences are frequently associated with a diagnosis of antisocial, narcissistic or borderline PD(38), those committed with violence can be associated with all types of PD, except, perhaps, the avoidant type(39,40). A significant association has been identified between schizoid and schizotypal personality trait and homicide/attempted homicide(40).
Over the past decades, there has been an increase in researchers’ interest in the relationship between violence and psychiatric disorders.
The treatment is equally important for individuals’ health and quality of life, as it is for public safety, especially for people with acute psychosis, where the symptoms could be the driving factor for the offence. Past violence, the association of alcohol and drug abuse along with environmental stressors are other variables that need to be taken into consideration.
Identifying and understanding the risk factors associated with violence in major psychiatric disorders is of great importance in the development of a comprehensive management plan that will contribute to reduce stigma and will allow patients to live independently in the community.