People with severe mental illness as the perpetrators and victims of violence: time for a new public health approach
Authors: Graham Thornicroft
Journal: The Lancet Public Health (2020)

People with mental illness are much more often the victims of violence rather than the perpetrators. However, people with some types of mental disorder are more likely to be violent than others in the general population, a fact that is uncomfortable for many in the mental health sector. While there is little evidence to suggest that people with mental illness in general (usually those with diagnoses of depression or anxiety disorders) have any increased risk of perpetrating violence compared with the general population,1Thornicroft G Danger or disinformation: the facts about violence and mental illness.in: Thornicroft G Shunned: discrimination against people with mental illness. Oxford University Press, Oxford2006: 125-149Google Scholar higher rates of violence perpetration have been identified among people with particular types of severe mental illness, namely schizophrenia and bipolar disorder. These rates are moderately raised compared with the general population, with an important caveat: people with triple morbidity (ie, individuals with severe mental illness and substance use disorder and antisocial personality disorder) are substantially more likely to be violent than people with severe mental illness alone.2Putkonen A Kotilainen I Joyal CC Tiihonen J Comorbid personality disorders and substance use disorders of mentally ill homicide offenders: a structured clinical study on dual and triple diagnoses.Schizophr Bull. 2004; 30: 59-72Crossref PubMed Scopus (72) Google Scholar The Article by Morwenna Senior and colleagues in The Lancet Public Health3Senior M Fazel S Tsiachristas A The economic impact of violence perpetration in severe mental illness: a retrospective, prevalence-based analysis in England and Wales.Lancet Public Health. 2020; 5: e99-106Summary Full Text Full Text PDF PubMed Scopus (19) Google Scholar tackles these difficult issues directly, and makes an important contribution to existing knowledge by estimating the costs of such violence, and by facilitating an informed discussion about the possible cost savings and social benefits of preventing such violence in future. Consideration of the scale of such violence is important. The authors calculated that 5·3% of all violent incidents in England & Wales in 2015–16 were committed by people with severe mental illness, which represents a considerable concern in terms of public safety, but relatively speaking, represents only a small proportion of the total number of violent acts committed in the whole population.4Walsh E Buchanan A Fahy T Violence and schizophrenia: examining the evidence.Br J Psychiatry. 2002; 180: 490-495Crossref PubMed Scopus (392) Google Scholar Regarding homicides in particular, which are often portrayed as the greatest concern in the media, those committed by people with psychosis are extremely rare. Indeed, homicides committed by people with psychosis were not included in the UN Global Surveys of Homicide,5Taylor PJ Kalebic N Psychosis and homicide.Curr Opin Psychiatry. 2018; 31: 223-230Crossref PubMed Scopus (7) Google Scholar and the number of such homicides is thought to have decreased over the past 50 years.6Large M Smith G Swinson N Shaw J Nielssen O Homicide due to mental disorder in England and Wales over 50 years.Br J Psychiatry. 2008; 193: 130-133Crossref PubMed Scopus (67) Google Scholar Senior and colleagues found that 31 homicides were perpetrated by people with severe mental illness in England and Wales during the study period. This finding is consistent with the data reported by Taylor and Gunn two decades ago, which showed that between 1957 and 1995, the mean number of homicides in England and Wales was 36 each year.7Taylor PJ Gunn J Homicides by people with mental illness: myth and reality.Br J Psychiatry. 1999; 174: 9-14Crossref PubMed Scopus (375) Google Scholar The most crucial issues addressed by this study are the costs of violence perpetrated by people with severe mental illness and the potential and value of a public health harm reduction programme. The potential cost savings appear substantial with a total annual societal cost of violence committed by people with severe mental illness in England and Wales of £2·51 billion (95% CI 1·37–4·52). However, although this work represents an important step, the authors were not able to directly estimate how much of this financial burden on society might be avoidable nor to assess which measures might most effectively and fairly reduce this burden. Improving access to mental health services is likely to be an important area to improve violence prevention. A substantial proportion of people with schizophrenia, for example, are not currently treated fully in accordance with clinical guidelines.8Patel MX Bishara D Jayakumar S et al.Quality of prescribing for schizophrenia: evidence from a national audit in England and Wales.Eur Neuropsychopharmacol. 2014; 24: 499-509Crossref PubMed Scopus (57) Google Scholar An additional limitation of this study is that the analyses did not account for concurrent antisocial personality disorders, which have been shown to substantially increase the risk of violence among people with severe mental illness.9Joyal CC Putkonen A Paavola P Tiihonen J Characteristics and circumstances of homicidal acts committed by offenders with schizophrenia.Psychol Med. 2004; 34: 433-442Crossref PubMed Scopus (89) Google Scholar It is clear that cuts in mental health service expenditure in England in the past decade have led to a reduced quality of overall care,10Docherty M Thornicroft G Specialist mental health services in England in 2014: overview of funding, access and levels of care.Int J Ment Health Syst. 2015; 9: 34Crossref PubMed Scopus (39) Google Scholar including a large scale national decommissioning of the assertive outreach teams that previously supported continuity of care for people with severe mental illness.11Hamilton I Lloyd C Bland JM Savage Grainge A The impact of assertive outreach teams on hospital admissions for psychosis: a time series analysis.J Psychiatr Ment Health Nurs. 2015; 22: 484-490Crossref PubMed Scopus (5) Google Scholar Public health approaches to violence reduction in the future therefore need to consider general factors associated with violence, such as access to weapons and socioeconomic deprivation, and issues specific to mental health, including continuity of care, appropriate treatment for people with severe mental illness, and effective interventions to reduce substance use disorders.12Large M Smith G Nielssen O The relationship between the rate of homicide by those with schizophrenia and the overall homicide rate: a systematic review and meta-analysis.Schizophr Res. 2009; 112: 123-129Crossref PubMed Scopus (86) Google Scholar, 13Rund BR A review of factors associated with severe violence in schizophrenia.Nord J Psychiatry. 2018; 72: 561-571Crossref PubMed Scopus (38) Google Scholar Future research is required to estimate whether the costs of such interventions might offset the health, criminal justice, and wider societal savings that would accrue from such a public health approach. I declare no competing interests. I am supported by the National Institute for Health Research (NIHR) Applied Research Collaboration South London, and by the NIHR Asset Global Health Unit award. The views expressed are those of the author and not necessarily those of the NHS, the NIHR, or the Department of Health and Social Care. I also receive support from the National Institute of Mental Health of the National Institutes of Health (Cobalt study). I am supported by the UK Medical Research Council in relation the Emilia and Indigo Partnership awards. The economic impact of violence perpetration in severe mental illness: a retrospective, prevalence-based analysis in England and WalesThe economic impact of violence perpetrated by individuals with severe mental illness is potentially important. Preventing violence, especially through services for individuals with comorbid substance misuse, and reducing recidivism might lead to cost savings at a governmental and individual level, in addition to the clinical and societal benefits. Full-Text PDF Open Access