From the Editor

After the mass shooting on Toronto’s Danforth, mental illness has been much in the news. The Canadian Psychiatric Association went so far as to warn against stigmatizing those with mental illness.

Despite stereotypes, studies show that people with mental disorders are more likely to be victims of violent crime rather than perpetrators. That said, the literature is light on how much crime patients experience, and the diagnoses of these patients.

This week, we look at a new paper just published by JAMA Psychiatry. Drawing on databases from Denmark, the University of New South Wales’ Kimberlie Dean and her co-authors consider crime (including violent crime) in a cohort study involving more than two million people. What do they find? Those with mental illness are much more likely to be victims than the general population.

gettyimages-126140612_superDenmark: old buildings and not-so-old data

In an accompanying editorial, Duke University School of Medicine’s Jeffrey W. Swanson and Charles M. Beldendiscuss the paper, and contrast it with American data. Their piece begins memorably: “The media-driven notion that mentally ill people pose a danger to others appears to be encrusted like a barnacle on the concept of mental illness submerged in the public mind.” They also weigh in on difference in rates of violence between Denmark and the United States.



Crime and Illness

“Risk of Being Subjected to Crime, Including Violent Crime, After Onset of Mental Illness: A Danish National Registry Study Using Police Data”

Kimberlie Dean, Thomas M.  Laursen, Carsten B. Pedersen, Roger T. Webb, Preben B. Mortensen, Esben Agerbo

JAMA Psychiatry, July 2018

People who experience mental illness are more likely to come into contact with the criminal justice system. Research to date has focused more on the association between mental illness and an elevated risk of crime perpetration than on the heightened vulnerability to being subjected to nonviolent or violent crime. However, evidence has emerged to indicate that risk of being subjected to crime may be at least as great, if not greater, than the risk of crime perpetration among persons with mental illness. Studies of individuals with severe mental illnesses, such as schizophrenia, have reported strikingly high rates of self-reported experiences of being subjected to crime. A survey of individuals in contact with secondary mental health services in London, United Kingdom, found rates as high as 40% for self-reported past-year experience of crime with any offense and 19% for past-year violent crime specifically compared with 14% and 3%, respectively, for a control sample obtained from a contemporaneous national crime survey. While increased risk of being subjected to crime among those with mental illness is in itself worthy of a preventive focus, its importance is further justified by evidence that being subjected to crime may be associated with a range of other adverse outcomes, including poor symptomatic and functional mental health recovery…

To date, the association between mental illness and risk of being subjected to crime has been examined mainly in cross-sectional surveys of selected samples of individuals with severe mental illnesses. Less is known about how risk might vary across the psychiatric diagnostic spectrum, specifically after onset of mental illness, or at a population level. Such an approach was previously undertaken to examine the association between mental illness and crime perpetration and found that risk after mental illness onset extended across the psychiatric diagnostic spectrum. While being exposed to crime, and violent crime in particular, is increasingly regarded as an important but largely neglected public health problem,the incidence of crime experiences by those with mental illness compared with the general population without such illness has not yet been established. Therefore, robust evidence is lacking to inform the development of preventive strategies, including initiatives aimed at improving the experience of persons with mental illness who report being subjected to crime and subsequently seek justice.

In this national cohort study, we examined for the first time to date in a population registry the incidence of being subjected to crime by all types of criminal offenses, and by violent crimes separately, after onset of mental illness across the full diagnostic spectrum…

dsc_21576Kimberlie Dean

So begins a paper by Dean et al.

Here’s what they did:

  • They drew from several Danish databases, and included those born between 1965 and 1998.
  • Basic demographic information was derived from the Civil Registration System.
  • “Data on individuals exposed to reported criminal offenses in Denmark were extracted from the Administrative System of the National Police, available from 2001 onward and including data on all offenses reported to police, including those not pursued after report.”
  • From the Psychiatric Central Registration, they could then gather information on admissions to psychiatric hospitals, as well as outpatient and ED visits; this database includes ICD diagnoses.
  • And from the National Crime Register, they extracted crime information.
  • Different statistical analyses were done, including a Poisson regression – “IRRs were calculated for each diagnostic category group vs a reference category of no recorded mental disorder.”

Here’s what they found:

  • “Among individuals in the cohort with any recorded mental disorder, rates of being subjected to crime were considerably higher, even after adjustment for sociodemographic factors, than those among individuals without mental disorder (IRR, 1.68… for men and IRR, 1.71… for women).”
  • “Considering each diagnostic category separately… positive associations between specific categories of mental disorders and the incidence of subjection to crime were found across the psychiatric diagnostic spectrum for both men and women, with the exception of developmental disorders (where a negative association was found) and intellectual disability for men (for which no statistically significant association was found). For both sexes, the strongest associations were observed for substance use disorders (IRR, 2.61 for men and IRR, 3.18 for women) and personality disorders (IRR, 2.23 for men and IRR, 2.00 for women).”
  • A similar pattern was observed for violent crime but “the magnitude of the associations was considerably greater…” with the adjusted IRRs for being subjected to violent crime among those with any mental disorder being 2.10 for men and 2.99 for women. In terms of diagnoses, substance use disorders were the most associated.

They conclude:

After onset of mental illness, individuals may experience a heightened vulnerability to being subjected to crime and violence. The focus to date in clinical practice and research on offending may have been at the expense of neglecting the risk of being subjected to crime, including violent crime. For example, risk assessment in clinical settings is dominated by consideration of risks of suicide and violence, while risk of crime receipt is largely ignored. Similarly, for those in contact with the criminal justice system, identification of mental health need and provision of support and treatment are offered almost solely to offenders. At a policy level, our findings have the potential to contribute to efforts to remedy public misconceptions about mental illness, often fueled by selective and pejorative media reporting, with the ultimate aim of reducing stigma.

A few thoughts:

  1. This is a good paper.
  1. The data is clear: those with mental illness are much more likely to be a victim of a crime than the general population – and that the association is even stronger for violent crime. And basically any mental diagnosis increased the likelihood.
  1. It should be noted that Dean et al. included reports of crime – not just criminal convictions.
  1. Studies that draw on national databases have huge data sets, of course. They are not without limitations. One limitation in this study: the diagnoses weren’t independently verified.
  2. Duke University’s Jeffrey W. Swanson and Charles M. Belden write the accompanying editorial: “The Link Between Mental Illness and Being Subjected to Crime in Denmark vs the United States: How Much Do Poverty and the Safety Net Matter?”

8acb0570d8-image_2860252Jeffrey W. Swanson

They open by putting the Dean et al. study in perspective:

The media-driven notion that mentally ill people pose a danger to others appears to be encrusted like a barnacle on the concept of mental illness submerged in the public mind. Meanwhile, epidemiological studies estimate that the overwhelming majority of the 44.7 million US adults with a mental illness are not violent toward others, but that 1 in 4 psychiatric patients are subjected to crime in a given year. That changes the story. The discovery that people with psychiatric disorders are far more frequently the targets, rather than the perpetrators, of crime has become a key talking point for advocates who would debunk the dangerousness myth. Until recently, the data to support this rhetorical reversal have come from relatively small samples of patients with psychiatric conditions and have relied on participant recall of being subjected to crime. Now, a new study from Denmark published in this issue of JAMA Psychiatry confirms that the onset of mental illness significantly increases risk of experiencing crime, using longitudinal registry data on a national cohort of more than 2 million individuals with independent measures of specific psychiatric diagnoses matched to police records of reported crime.

The paper weighs the differences between the rates of crime in Denmark and the United States, noting that methodological differences provide a partial explanation.

They go on to argue:

The association of mental illness with low socioeconomic status (with its attendant risk of exposure to crime) is likewise one of the most well-established findings in psychiatric epidemiology. The long-running debate on social selection vs social causation has never been lost or won, but most students of the matter now concede that both processes happen. On the one hand, people with disabling psychiatric disorders like schizophrenia tend to have truncated opportunities for educational attainment, poor employment experiences, stunted development of social capital, and constrained access to resources. Consequently, many are downwardly mobile and end up impoverished. On the other hand, the conditions of grinding poverty, in which stressful and traumatic life events occur more frequently and with more deleterious effect while coping resources may be in short supply, are not good for anyone’s mental health.

  1. Past Readings have considered this topic. A Reading from February 2017, for example, considered the Monahan et al. paper. The authors looked at the experience of post-hospitalized patients, finding that the majority (58%) were victims or perpetrators of violence (including self-violence) within a year of hospitalization. You can find it here:
  1. There are many differences between the two papers (Swan et al. drew from a national database and considered all crime; Monahan et al. focused on a sample of patients who were post-hospitalization and considered violence). There is a common connection, though: the lives of those with mental illness can be harsh.


Reading of the Week. Every week I pick articles and papers from the world of Psychiatry.