Major Mental Disorders and Violence: A Critical Update

Current Psychiatry Reviews, 2007, 3, 33-50 33

1573-4005/07 $50.00+.00 © 2007 Bentham Science Publishers Ltd.

Major Mental Disorders and Violence: A Critical Update

Christian C. Joyal*,a,b

, Jean-Luc Dubreucqa,c

, Catherine Gendronb and Frederic Millaud

a,c

aPhilippe-Pinel Institute of Montreal, Canada

bDepartment of Psychology, Université du Québec à Trois-Rivières, Canada

cDepartment of Psychiatry, Université de Montréal, Canada

Abstract: The possibility of a causal link between major mental disorders (MMDs) and violence has been the matter of a

debate for decades in psychiatry. Just as a consensus seemed to emerge, a standout and unprecedented large-scale com-

munity investigation lead to contradictory conclusions. The main goal of this review was to provide clinicians with a criti-

cal summarizing of all major relevant studies published during 15 years. It is concluded that major mental disorders per

se, especially schizophrenia, even without alcohol or drug abuse, are indeed associated with higher risks for interpersonal

violence. However, further stigmatization of persons with MMDs should be considered, as between 85% and 95% of

community violence is not related with MMDs and the absolute number of assaults committed by psychiatric outpatients

is low. A summary Table 1 includes comments and conclusions related with each reviewed study and circumstances re-

lated with this type of assaults are discussed. Interpersonal violence associated with MMDs seems to be due to a hetero-

geneous minority of patients and current research aims at better characterizing subgroups who assault in similar contexts.

Keywords: Psychiatry, major mental disorders, violence, prevalence, circumstances.

INTRODUCTION

In psychiatry, the last quarter of century witnessed im-portant fluctuations of position regarding the link between major mental disorders (MMD) and violence. Shifts of per-ception about schizophrenia (Sz) are well illustrated in the last publications of the American Psychiatric Association Diagnostic and Statistical Manual (DSM), which stressed in 1987 ([1], p.191) that “Although violent acts performed by people with [schizophrenia] often attract public attention, whether their frequency is actually greater than in the general population is not know”; followed in 1994 ([2], p. 280) with “There is conflicting evidence with regard to whether the frequency of violent acts is greater than in the general popu-lation” and; more recently (2000; [3], p. 304), with “Many studies have reported that subgroups of individuals diag-nosed with schizophrenia have a higher incidence of assaul-tive and violent behaviors”. In the meantime however, an ambitious and influential community follow-up investigation involving more than a thousand participants lead to the con-clusion that without signs of alcohol or illegal drug abuse, psychiatric outpatients, including those with schizophrenia, are not more frequently or severely violent than their neigh-bors [4-6]. For clinicians, the situation needs to be clarified. The main objective of this investigation was to review recent and influential studies concerning this controversial issue and underline important factors to consider when judging the conclusions. A secondary goal was to describe common con-texts and circumstances associated with this type of violence to define more homogeneous subgroups of aggressive pa-tients, which would help establishing better prevention strategies. Notwithstanding the insidious tendency of further stigmatizing persons with a MMD (e.g. [7,8]), and the unfor-

*Address correspondence to this author at the Philippe-Pinel Institute of

Montreal, Research Center, Montréal, Québec PQ H1C 1H1, Canada; Tel:

514 648-8461, Ext. 623; Fax: 514 881-3701;

E-mail: [email protected]

tunate fact that a disproportionate number of psychiatric out-patients are victims, not instigators of violence [9], the exis-tence of a significant and causal link between severe mental illness without a substance use disorder (particularly Sz), and elevated risks for violence seems to be increasingly ac-knowledged (for reviews, see [10-13]. While stigmatization and generalization of characteristics related to minority sub-groups should clearly be avoided, asserting that MMDs are definitely not associated with higher risks of committing violence (e.g. [14]) might also be premature. This review is a survey of the data published between 1990 and 2004 con-cerning the presence or absence of a link between psychiatry and violence. The number of methodologically-sound inves-tigations in this field is too limited to conduct an evidence-based review or a meta-analysis. Moreover, the exhaustive list of all bias associated with this type of investigation is not included here, as numerous critics and editorials have al-ready been published to this end (e.g. [15-19]).

METHOD

A search for all empirical studies published between 1990-2004 and reporting rates of interpersonal (as opposed to verbal or threatening) community (as opposed to inpa-tient) violence, committed by a person with a major mental disorder (including psychotic, mood or anxiety categories; as opposed to an exclusive Axis II disorder) was first per-formed with three traditional databases (Medline, PsychInfo and Current Content; using the word mental disorder or men-tal illness paired with either assault, violence or homicide). Prior to 1990, this type of studies contained serious and nu-merous methodological flaws [20] and therefore were not considered here (see [21] for a critical review of these older studies). Also included were any additional and related in-vestigations cited in the studies found with the search and published since 1990. Then, seminal papers cited in more than one hundred subsequent publications were identified (N = 7 according to the databases of the Web of Science, Sci-

Not For Distribution

34 Current Psychiatry Reviews, 2007, Vol. 3, No. 1 Joyal et al.

ence Citation Index of Thomson Scientific, www.isinet. com), and all these subsequent references were consulted to ascertain they were included in the present review. Once these searches were performed, only papers reporting em-pirical data and written in English were kept. Finally, a summary Table 1 was created with descriptions and com-ments related with each investigation. In evaluating these studies concerned with MMDs and violence, several meth-odological aspects should be considered (for details of strengths and weaknesses related to this field of research, see for instance [6,19]). When available, these aspects are speci-fied in the summary Table 1. Thus, the specific diagnoses of MMD are reported (allowing finer comparisons than consid-ering mental illness as a whole), with and without additional diagnoses of substance misuse and personality disorders (since they are themselves associated with violence among persons with a MMD, e.g. [4, 22]). Gender is also specified, with an emphasis for data concerning men (women in the general population are so markedly less violent than men that odds ratios for violence among women with mental ill-ness are invariably high). Also, only rates of serious physical violence toward others were included since the dynamic of violence toward self or objects is highly different. The dif-ferent definitions of violence were also specified because they tend to vary from one report to another (e.g. only as-saults leading to an injury vs verbal threats). The methods employed for registering violent acts (official/police records only, which underestimate reality or additional face-to-face interviews with the participant and/or consultation of a col-lateral informant), and the period considered (prospectively or retrospectively; in terms of weeks, years or lifetime, just prior or after the hospital admission) are also given. The place of recruitment (e.g. only discharges from hospitals or the general population) and the total number of participants including the controls, the number of participants with a MMD, and both the absolute numbers (high percentages might simply reflect the rarity of the occurrence) and per-centages of violent patients are provided (not only the odds ratios). The type of comparison groups (general population, persons with other mental illnesses or both) and the country where the study was conducted are also indicated because occurrence of MMDs such as Sz is rather similar worldwide (e.g. [23]), which would inflate percentages of violence committed by persons with a MMD in societies where vio-lence rates are low (e.g. Scandinavian countries). Finally, homicides are considered separately as they represent an extreme act and similar rates of homicides committed by persons with Sz have been reported irrespective of the coun-try, including the United States (see [24] for a discussion).

RESULTS

Twenty-two studies concerned with the link between MMDs and violence met the criteria of the search and were published between 1990 and 2004 (Table 1). These articles were also cited by others at least 30 times (when published between 1990-2000; Science Citation Index) and appeared in scientific, peer-review journals with an impact factor of 2.5 or more (2004 edition of the Journal Citation Report; www.isinet.com).

Ten main observations emerge from this review: 1) com-pared with the general population and independently of drug or alcohol consumption, MMDs are associated with signifi-

cantly higher risks for physical violence against others. Once gender, age, socio-demographic and socio-economic status are taken into account, the overall risk for physical assault is generally estimated to be 3 to 5 times higher than that of the general population; 2) The landmark MacArthur study seems at odd with other investigations [6] and given the importance and impact of the study, it deserves further discussion; 3) The absolute number of violent psychiatric outpatients is very low however, and only minority subgroups are con-cerned; 4) Sz is generally associated with higher rates of interpersonal violence than other MMDs; 5) Three sub-groups of potentially violent patients with Sz are currently defined, including one with multiple co-morbid diagnoses; 6) Factors associated with violence in the community also in-fluence psychiatric outpatients, both at sociodemographic (e.g. neighborhood, socioeconomic status, education levels, unemployment) and individual (e.g. alcohol or drug use dis-orders, a history of antisocial behaviors) levels, especially among men; 7) Rates of fatal violence (toward self or others) are more particularly elevated among persons with MMDs; 8) Interpersonal violence committed in the community by persons with a MMD usually involves someone they know and rarely occurs in public places; 9) Few studies aimed at characterizing protective factors for psychiatric violence; 10) In a near future, sufficient well-design studies will be avail-able to conduct evidence-base studies, or at least meta-analysis.

DISCUSSION

A convincing demonstration of a significant or non sig-nificant link between violence and psychiatric diagnoses was beyond the scope of this review, as it will only be possible with a sufficient number of well-designed studies (allowing meta-analysis for instance). Still, the main goal of this de-scriptive survey was to thoroughly report the findings of investigations concerned with MMDs and interpersonal community violence published during 15 years. This survey strongly suggests that persons with a MMD are at higher risks to commit a violent act in the community than persons without a MMD. Although this suggestion results more from the quantity than the quality of available data, the conver-gence of evidence is noteworthy (Table 1). Important meth-odological factors should be considered when evaluating these studies, including selection bias, comorbid substance abuse, antecedent of violence, compliance to medication, parental and neighborhood socio-economical levels, gender, and country of residency (see the Method section and refer-ences 6 and 19). Although recent investigations commonly took these possible confounding factors into account, a sin-gle study could not possibly avoid them all since every framework is associated with both strengths and weaknesses. For instance, while epidemiological studies offer strong sta-tistical power, they allow little information concerning the motivation to assault since individual interviews with the participants are not possible. Future investigations might also consider other factors such as the timing of the MMD diag-nosis in relation with the timing of violence and the matter of medication administration and compliance. When diagnoses are confirmed (e.g. with the SCID), posed recently, and when medication compliance is assured, risks for violence are reduced. They still remain significantly higher than those observed among the general population however.


Major Mental Disorders and Violence Current Psychiatry Reviews, 2007, Vol. 3, No. 1 35

Table 1. Main Findings of the Principal Studies Published Between 1990 and 2004 Concerning the Link Between MMDs and Vio-

lence Against Other Persons

Reference N/Diagnosis % Violents N Violents O-Ra Type of Violence Period Considered

114 ( & ) with schizo-phrenia-schizophreniform

including:

26 without substance abuse

3 with substance abuse with-

out a third diagnosis

12,7%*

8,4%*

30,3%*

14 (estimates based on weighted N)

2

1

NI

620 ( & ) with a mood disorderb

including:


29 with substance abuse

without a third diagnosis

Ave.: 11,1%*

3,5%

29,2%*

69

5

8

NI

1687 ( & ) with an anxiety disorder c

including:


119 with substance abuse

without a third diagnosis

Ave. 9,1%*

2,4%

20,3%*

154

28

24

NI

533 ( & ) with SUD onlyd 21,3%* 114 NI

Swanson et al., 1990 [25]

N total: 10 059

U.S.A.

8066 ( & ) without a diagnosis of mental disorder

2,1%

165

…

Self-reported physical violence

toward others (indi-vidual interviews)

The preceding year

A pioneer, classical report. These data were derived from the NIMH Epidemiologic Catchment Area (ECA) project, consisting of large U.S. surveys about the prevalence of mental disorders in the community. This project was not designed to assess aggressive behaviors however; measures of violence were

indirect. The prevalence of SZ and AF was 3 times higher among respondents who were violent than among those who were not. The difference was less important among persons with diagnosis of AX. Although substance abuse was associated with the highest risks for violence (by far), individuals with a

psychiatric disorder without a SUD were still 3 to 4 times more likely to report assaultive behavior than those without any diagnosis. Among persons with no mental disorder, 2.1% reported violent behavior in the last year, compared with 12.7% of the persons with schizophrenia (including 8.4% without a

SUD). Violence was not significantly more (or less) prevalent in persons with schizophrenia than among those with other disorders. The absolute prevalence for violence is low and 92% of persons with schizophrenia only who live in the community were not violent by their own account during the past year.

Conclusion: public fear of persons with schizophrenia living in the community is largely unwarranted, though not totally groundless.

Lindqvist and Allebeck, 1990 [35]

Sweden

644 ( & ) with schizo-phrenia

including 330

5%

8,5%*

32

28

3,9* Registered vio-lent offences

The 14 years fol-lowing discharge from hospital

Another influential study. After hospital discharge, the rate of violence among outpatients with schizophrenia was about 4 times higher than that of the general population. Co-morbid substance abuse was not considered, however.



(Table 1) contd…..


365 ( & ) with a psychiat-

ric diagnosis

12,3%*

45

NI

Link et al., 1992

[26];

Link and Stueve, 1994 [82]

U.S.A.

385 ( & ) residents of the same neighbourhood without lifetime psychiatric admis-

sion.

5,2% 20 NI

Hitting others, self

report (individual interviews)

During the past year

or month

The second large U.S. community survey linking psychiatric diagnoses and violence. The group with a psychiatric diagnosis was recruited from outpatient and inpatient community services. Patients had significantly higher rates (up to three times) on measures of violence (hitting others, but also fighting,

weapon use and hurting someone badly) than their neighbors after sociodemographic and community context factors were controlled. This study is re-nowned for its findings about a higher incidence of a cluster of three psychotic symptoms related with feeling of threat or being controlled among violent

patients. However, the temporal association between the occurrence of these symptoms and violent acts was not established. Data were not separately re-ported for each type of diagnosis and the impact of SUD was not assessed.

82 with a MMDe

including:

(47) without SUDd

(35) with SUD

14,6%*

NI

NI

12

4,2*

1,7

8,4*

156 with SUD d

49,4%*

77

15,4*

Hodgins, 1992 [30] and

Hodgins, 1993

[92]

N total: 14 401

Including 7362

Sweden

6947 without admission for a mental disorder

5.7%

396

…

Criminal record for a violent of-

fense against oth-ers, including

threatening

Lifetime

While almost half of the persons with the diagnosis of a SUD had a criminal record for a violent crime, the odds ratio for a registered violent crime were only 1.7 for men with a major mental disorder without a SUD. However, this was based on 47 persons and the criminality rates were remarkably high for

the general population (e.g. 29.4% of male in this study according to Hodgins, 1993, including this 5.7% for a violent crime). No data were available for schizophrenia only or other particular diagnosis.

3130 with a MMDf

Ave: 5,7%*g

178

Ave: 3.5 *

1731 with SUD only

Ave: 9,1%*

158

Ave: 5.4*

Hodgins et al., 1996 [31]

N total: 324 401

Including 165 602

Denmark

155 580 without psychiat-ric hospital admission

Ave: 1,7%

2645

…

Criminal record for a violent

offense involv-ing interpersonal

aggression or a threat thereof

Lifetime

The proportion of violent offenders with a major mental disorder was significantly higher than that of the general population. Understandably, the absolute

number of violent persons with a psychiatric diagnosis is low compared to that of the persons without it. Separated data for different diagnoses of major mental disorders were not available, including those for persons with co-morbid SUD. As expected, a diagnosis of SUD was associated with the higher risks

for violent offenses.

Modestin

& Ammann, 1996 [93]

Switzerland

282 Schizophrenia

282 general population

15%*

3%

5

1

5.2*

Conviction re-

cords for violent crime (not de-

fined)

Lifetime

Men who has been hospitalized at least once for sz were 5 times more likely to received a conviction for a violent crime than men from the general popula-

tion matched for age, marital status, occupational level and community size.





Eronen et al.,

1996 [40]

1302 homicide offenders

Finland

86 Schizophrenia

including:

(38) without AUD

(48) with AUD

6.6% of offend-

ers compared with 0.7% of the

general popula-tion

86

38

48

10,0*

7,3*

17,2*

Homicide

From 1980 to 1991

inclusively

Men receiving a co-morbid diagnosis of sz and alcohol abuse/dependence were 17 times more at risk of committing homicide than men from the general population. Szalone still elevated the odds ratios by about sevenfold, a highly significant increase.

Tiihonen et al., 1997 [32];

Räsänen et al.,

1998 [94]

N total: 5636

Finland

51 with schizophrenia

including:

(40) without AUD

(11) with AUD

13.7%*

7.5%*

36.4%*

7

3

4

7,0*

3,6*

25,2*

Homicide, as-sault, robbery,

arson or violation of domestic

peace

Lifetime

5285 without a diagnosis of mental disorder

2,2%

117

…

A unique diagnosis of sz was associated with a significantly higher odds ratio of committing a violent act against someone. The risk of violent offenses was highest for the co-morbid diagnosis of schizophrenia and alcohol abuse. Again, the absolute number of violent offenders with schizophrenia is low.

Stueve and Link,

1997 [27]

N total: 2678

adults aged be-tween 24-33

interviewed by psychiatrists in

the community

Israel

29 ( & ) with a psychotic

disorderh

123 ( & ) with bipolar

disorder

(131) with a psychotic or bipolar disorder without SUD

including:

(17) with a psychotic or bipo-

lar disorder and SUD

(4) psychotic or bipolar dis-order and APD

519 ( & ) with major de-pression without psychotic

episodes

431 ( et ) with an Axi

835 with an Ax or major

depression without SUD

28,9%*

23,7%*

20,7%*

39,3%*

93,4%*

11,0%

Ave.: 9,4%

8,6%

8 (estimated)

29

27

7

3

57

41

72

NI

Fighting, self-

report (individual interviews)

During the past five

years





64 with an Ax or major de-pression and SUD

51 with an Ax or major de-pression and APD

26,1%*

56,2%*

17

29

NI

52 ( & ) with APD

51,6%*

27

NI

77 ( & ) with substance abuse only

25,1%*

19

NI

1447 ( & ) receiving none of the above diagnoses

7,0%

101

NI

A third community-based epidemiological investigation based on face-to-face interviews. Self-reports of fighting (derived from the Psychiatric Epidemiol-

ogy Research Interview) were significantly more elevated among persons who received a diagnosis of either psychotic or bipolar disorder than respondents without one of the assessed psychiatric diagnoses, which was not the case for persons with major depression or an anxiety disorder. The very low proportion

of substance abuse among these young Israeli adults allows controlling for lifetime substance abuse. APD and demographic characteristics were also con-sidered. As expected, substance abuse and APD were associated with high rates of violence and each increased the risks among persons with a psychiatric

diagnostic. The association between the psychiatric disorders and violence also decreased with higher years of education. Again, the absolute number of community violence associated with psychotic disorders is low.

Volavka et al., 1997 [38]

N total: 1017 persons with SZ

10 different coun-tries

531 ( & ) with sz and first consultation for psychotic

symptoms

10,5%*

56

NI

Assaulting another person physically

(individual inter-views)

Lifetime

Approximately 10% of those with first-contact in 7 developed countries admitted having assaulted someone at least once in their life. The proportion was 31.5% in the 3 developing countries (N=153). Overall, 7% of the assaults occurred before, 58% coincide with, and 35% followed the onset of psychotic symptoms, although the temporal range of “coinciding” is not specified. However, these data were derived from a questionnaire built for a project not de-

signed to study violence, as it was the case for the aforementioned epidemiologic studies. History of assault was associated with certain behaviors that might be related to psychotic symptoms (e.g. being very excited for days and trying to do too many things at once), although these behaviors were also inferred

from the interview instrument. Neither the causal nor the temporal link between these inferred symptoms and the assaults were determined. The risks for aggression were significantly associated with lower age, lower SEC, lower education attainment and higher alcohol use, as it is observed among persons

from the general population. Men and women with Sz were assaultive in similar proportion (22.6% and 17.9%, respectively).

Belfrage, 1998 [33]

Sweden

1056 ( & ) with a psy-chotic disorderj

13%*

137

NI

Criminal register for a violent crime

(mur-der/manslaughter

assault, illegal threat or violence

against officers).

Ten years following hospital discharge

File-based study involving 1056 patients with a psychotic disorder 10 years after their hospital discharge. Thirteen percent of these patients were sentenced at least once for a violent crime during that period. The proportion of persons with schizophrenia, with or without SUD is not specified, although one third of the 639 persons with schizophrenia were registered for a crime (property, violent, sexual or else). No comparisons with the general population were pro-

vided for violent crimes.






including:

(32) without SUD

(34) with SUD


including:

(7) without SUD

(4) with SUD

3.3% of male

violent offenders (estimated)

1.6%

1.7%

7.2% of male

homicide of-fenders

4.6%

2.6%

4,4*

2,4*

18,8*

10,1*

7,1*

28,8*

Conviction for

interpersonal violence

Conviction for

homicide

40 with an affective disor-

der

including:

(26) without SUD

(14) with SUD

4 with an affective disorder

including:

(3) without substance abuse

(1) with substance abuse

2% of male

violent offenders

2.6% of male homicide of-

fenders

4,1*

2,9*

19,0*

5,4*

4,4*

17,5*

Conviction for

interpersonal vio-lence

Conviction for homicide

169 with SUD only

8 with SUD only

4.2% of male violent offenders

5.3% of male homicide of-

fenders

9,5*

5,7*

Conviction for interpersonal vio-

lence

Conviction for

homicide

Wallace et al.,

1998 [39]

N total: 4156 ( & ) found guilty

of a serious crime, including

3838 , of which 1998 were

guilty of a violent offence and 152

of homicide

Australia

51 with a personality dis-

order

6 with a personality disor-der

2.6% of male

violent offenders

4.0% of male

homicide of-fenders

18,7*

28,7*

Interpersonal vio-

lence

homicide

Between 1993 and

1995 inclusively

The first of three studies based on a Australian psychiatric case register, it reported that persons with schizophrenia or an affective disorder were signifi-cantly more likely to be convicted for different types of crime, including interpersonal violence and homicide, than persons from the general population,

even without a SUD. Sz was diagnosed in approximately 3.3% of violent male offenders compared with 0.7% of the general population. As usual, substance misuse and personality disorders were over-represented among convicted persons. Again, substance abuse disproportionately increased the link between the

mental illnesses and violence, but elevations remained significant without a SUD. While 99,97% of persons with schizophrenia did not commit homicide during the study period, the annual risk for homicide in Australia was 1 for 3000 among men with schizophrenia compared with 1.0 to 1.4 for 100 000 men

in the general population. Approximately 7% of male homicide offenders received a diagnosis of schizophrenia, and those without a SUD were 7 times more at risk for homicide than men from the general population. As concluded by the authors, however, the actual risk that a person with a major mental

disorder commits a serious crime in the community is low.





Steadman et al.,

1998 [4];

Monahan et al., 2001 [6]

One-year follow-

up and interview investigation

U.S.A.

951 ( & ) with an admis-

sion chart diagnosis of a psychiatric disorderk and at

least one follow-up completed

including:

MMDl without symptoms of SUD

MMD with symptoms of SUD

Primary research diagnosis of Sz (n 162 or 17%)

Primary research diagnosis of

major depression (n 399 or 40%)

Primary research diagnosis of bipolar disorder (n 132 or

14%)

(The percentages are not

precisely the same in the two reports)

519 ( et ) Residents of the

same neighborhood

including

(428) without signs of SUD

(91) with signs of SUD

27.5%*

17,9%*

31,1%*

14,8%*

28,5%*

22,0%*

4,6%

3,3%

11.1%

n=262

n=24

n=24

n=14

n=10

Battery resulting in

physical injury, sexual assaults,

assault with a weapon, threats

with a weapon. Based on self

report, interview with a collateral

and official records

At least 10 weeks after

hospital discharge, up to 50 postdischarged

weeks.

Preceeding 10 weeks

This tremendous, large-scale community study involved 951 outpatients successfully interviewed and followed at least once (564 patients were interviewed

5 times, every 10 weeks, for a year, 49.6%). Thus, the prevalence rates for violence in the community associated with psychiatric diagnoses were directly addressed. As much as 27.5% of outpatients have been physically violent toward others during the year and 17.9% of those did not report symptoms of

SUD. An appreciable proportion of outpatients with schizophrenia have been assaultive (14.8%), although higher rates were associated with major depres-sion or bipolar disorder. Interestingly, the same estimated number of persons with schizophrenia (in the course of at least 10 weeks) and without MMD

(during the last 10 weeks) have been violent in the community: 24. Of course, substance misuse was associated with the largest part of reported violence, both among outpatients and the general population. This study confirmed that the majority of discharged psychiatric patients are not violent and when they

are, it is more likely to occur during the first 20 weeks, in association with SUD. See the text for more detailed comments about this unique investigation.





631 Schizophrenia (first

admission)

Average be-

tween 1975 and 1985: 11,1%*

Average between

1975 and 1985: 7.0*

Conviction for a

violent crime

Lifetime

Mullen et al.,

2000 [37]

Australia

631 General population

group matched for age and place of residence

Ave: 1,6%

…

This second report based on the Australian (Victoria) Psychiatric Case Register confirmed that outpatients with schizophrenia were significantly more likely to be convicted for criminal offences, including violence, than their neighbors, both in their lifetime and during the 10 years following hospital discharge. As

expected, substance abuse disproportionately increased the risks. Comparisons were also made between convictions of years 1975 and 1985 (before and after deinstitutionalization). Although the number of convicted persons with schizophrenia was significantly higher in 1985 than 1975, a similar increase

was registered among the general population, suggesting that deinstitutionalization could not be causally associated with this rise (see also Wallace et al., 2004).

Brennan et al., 2000 [29]

N= 335 990 et

Denmark

1143 with Schizophrenia

including:

(846) without SUD

(297) with SUD

11,3%*

7,1*

23,2*

n = 129

n = 60

n = 69

4.6* Adjusted for marital status, SE

and PD: 1.9

2,8*

NI

Criminal record for a violent act.

(murder, attempted murder, rape, vio-

lence against authority, assault,

domestic violence or robbery)

Lifetime

729 with a mood disorderb

including:

(559) without SUD

(170) with SUD

5,2%*

3,2%

11,8%*

n= 38

2.0 (adjusted for marital status, SE

and PD: 0.8)

1.2

NI

163 727 without hospitali-zation for a psychiatric disor-

der

With SUD

2,7%

NI

…

…

A large birth cohort study concluding that men (and women) with schizophrenia are significantly more at risk to be arrested for violence than persons who had never been hospitalized for a psychiatric disorder, even after controlling for socioeconomic status, substance abuse and personality disorder. However,

the odds ratio for a violent record dropped from 4.6 to 1.9 when these factors were considered for men with schizophrenia. Men with schizophrenia without SUD were nearly 3 times more likely to be arrested for violence than men without a psychiatric admission. Diagnoses of a mood disorder were not signifi-

cantly associated with higher rates of arrests for violence.





Arseneault et al., 2000 [28]

961 ( et )

New-Zealand

39 ( & )

with schizophrenia spectrum disorder

172 ( & ) major depres-sion or dysthymia

170 ( and ) with an anxi-ety disorderm

94 ( & ) with alcohol dependence

572 ( & ) without psychi-

atric disorder

33,3%*

15,7%*

12,4%*

25,5%*

3,8%

n = 13

n = 27

n = 21

n = 24

n = 22

(Adjusted for gender, SE and comorbid

diagnoses)

2.5

1.7

1.0

1.9

…

Official records for criminal violent acts

and self-report vio-lence using direct

interviews (assault, aggravated assaults,

rape, robbery, and gang-fighting).

Preceding 12 months

Odds ratio for violence among young adults (21 y.-o.) suffering from schizophrenia is 2.5 compared to young adults without a psychiatric disorder. In oppo-

sition, the anxiety disorder diagnoses were not associated with significantly higher risks for violence. Interestingly, violence committed by persons with a schizophrenia-spectrum disorder was best explained by either perception of threat or a history of conduct disorder, suggesting heterogeneous roots for this

type of violence.

Milton et al., 2001 [36]

U.K.

166 ( & ) with first epi-sode psychosis

9,6%*

n = 16

NI

Medical records, legal reports, and

direct interviews documenting serious

aggression (weapon use or threat, sexual

assault or any assault resulting with injury

to a victim)

Between the first evidence of behav-

ioral modifications associated with onset

of psychosis to 3 years after first con-

tact.

Follow-up study without a comparison group involving persons with first episode of psychosis, including schizophrenia. Being male, single, and unem-

ployed were significantly associated with aggressive behaviors. In accordance with the MacArthur data (Appelbaum et al., 2000), evidence of “TCO” psy-chotic symptoms at admission had no predictive value for future violence among outpatients who were successfully recontacted several months after dis-

charge (being even associated with lower risks for future violence). Again, a minority of victims was total strangers (17%).

Erb et al., 2001 [41]

Germany

29 ( & ) with schizophre-nia

261 ( & ) without schizo-

phrenia

100%

100%

16,6*

Homicide or at-tempted homicide

Between 1992 and 1996

Of 290 persons judged to have committed or attempted homicide between 1992 and 1996 in the city of Hessen, 29 had a diagnosis of schizophrenia (10%). Interestingly, a similar proportion of homicide offenders (276/3367; 8.2%) was found between 1955 and 1965 in Germany, before deinstitutionalization. in

both era, less than 10% of the victims were strangers.

Hodgins et al.,

2003 [34]

Canada, Ger-

many, Finland and Sweden

128 with schizophrenia or

schizophreniform

including (112)

7.0%

10.2%

n= 9

n = 11

Direct interviews

and collateral information for

serious violent acts (criteria of Stead-

man et al., 1998).

6 months after dis-

charge

Between 6 and 12

months after discharge

Follow-up study of discharged out patients with schizophrenia. No comparisons were made with a control group. Although the majority of participants were

recruited in forensic settings (n = 91), only 16 (12.5%) have been violent at least once in the community during the 12 months following discharge. Sixty-nine percent of these offenders already had a criminal record for violence and 62% had a comorbid diagnosis of alcohol abuse.





Fazel and Grann,

2004 [42]

Sweden

1625 ( & )

including:


50 with a bipolar disorder

131 with other psychosis

(includes drug-induces and organic)

161 without a psychiatric

diagnosis

11.0%*

3.1%

8.1%

9.9%

NI

Conviction for

murder or man-slaughter

From 1988 to 2001

File-based study linking convictions for homicide with psychiatric diagnoses. Bipolar disorder was found in lower proportion than schizophrenia or absence

of diagnosis. Eleven percent of homicide offenders received a diagnosis of schizophrenia (compared with 0.7% of the general population) and only 10% did not have a psychiatric diagnosis.

Schanda et al.,

2004 [46]

Austria

1087 ( & )

including:

58 with schizophrenia or

schizophreniform disorder

(41 without AUD)

(17 with AUD)

(41 )

(17 )

14 with major depression

and 1 with a manic episode

(9 without AUD)

(6 with AUD)

5.3%

3.8%

4.3%

13.5%

1.4%

0.8%

0.6%

8.8*

7.1*

6.5*

25.9*

0.6

0.4

3.1

Have committed

murder or man-slaughter

From 1975 to 1999

File-based study determining the rate of homicide offenders found not guilty because of MMDs. The association between MMD and odds of committing homicide was significant and entirely due to schizophrenia. Without an alcohol use disorder, schizophrenia is associated with an odd ratio of 7.08 to commit

a homicide compared with the general population (the number of men with Sz and AUD is not specified). In opposition, major depression and bipolar disor-der were not associated with increased odds of homicidal act.



Evidences that Persons with a Sz are More Frequently Violent as a Group Than Persons Without a Psychiatric

Diagnosis

Four main types of investigations published between 1990 and 2004 have reported a significant link between in-terpersonal community violence and severe mental illness (see the Table 1 for a description of these investigations). Large epidemiological studies [25-27]; longitudinal studies of birth cohorts [28-32]; follow-ups of discharged hospital patients [24,33-39]; and investigations among homicidal populations [40-42]. As none of these is exempt of possible methodological bias, the strength of the link rests essentially on their number and the variety of approaches they em-

ployed. The well-known MacArthur study, which prompted divergent conclusions, will be discussed later.

Are Specific Diagnoses of MMD Associated with Differ-ent Risks for Violence?

Distinguishing diagnoses of MMD might prove crucial for assessing risks of future violence, although available data are scarce and disparate. While anxiety disorders are gener-ally associated with lower risks for violence than psychotic or mood disorders [25,27,28], only few and divergent results are available concerning the distinct rates of MMD diagno-ses. It is still difficult to determine whether any particular MMD is associated with higher violence risks, although rates of serious violence could be as high as 7.5% to 8.5% among



Wallace et al., 2004 [24]

Australia

2861 ( & ) with schizo-phrenia

including:

(n ?) without SUD

(n ?) with SUD

(1689 ) schizophrenia

(1269 ) without SUD

420 with SUD only

2861 ( et ) general popu-lation, matched for gender,

age and place of residence.

including:

(1689 )

8,2%*

4,4%*

26,1%

13,0%*

7,4%*

29,7%

1,8%

2,9%

4,8*

2,5*

7,7*

5,0*

2,7*

14,1

Criminal record for serious interper-

sonal violence.

Lifetime

The third study based on the Victorian psychiatric case register. Instead of determining the rates of psychiatric diagnoses among convicted persons (Wallace et al., 1998), this study examines the rates of criminal convictions among 2 861 persons with first admission for schizophrenia. Schizophrenia without SUD

is significantly associated with higher risks for community violence. Again, substance misuse is linked with disproportionate figures. An especially high rate of homicide behaviors was found among persons with schizophrenia (1 for 572 compared with 1.2 for 100 000 among the general population), although this

represents only 5 homicide offenders with schizophrenia. It is estimated that 6% to 11% of the community violence is attributable to schizophrenia. How-ever, deinstitutionalization is not directly responsible for higher frequency of community violence: numbers of violent acts due to psychiatric outpatients

increased in parallel with those committed by the general population between 1975 and 2000..

aOdds ratio compared to the general population. For instance, an odds ratio of 2 for a subgroup represents a twofold increase in the odds (risk) of violence for this subgroup, which is

2 times more likely to be violent than the general population. An odds ratio of 2.5 is generally considered as the lower limit of a strong association between dichotomous variables (although dependant of the confidence interval) (10). bMajor depression, mania or bipolar disorder. cPhobia, panic disorder or obsessive-compulsive disorder. dIncludes alcohol and/or illegal drug abuse or dependence. eSchizophrenia, schizophreniform disorder, schizoaffectice disorder, other psychotic disorders, bipolar disorder or major depression. fSchizophrenia, manic-depressive psychosis, psychogenic psychosis or other psychosis. gAverage of two consecutive eras (1959-1977 and 1978-1990). hSchizophrenia, schizoaffective disorder, unspecified functional psychosis and major depression with psychosis. iGeneralized anxiety disorder or phobia. jIncludes diagnoses of schizophrenia (N = 639) affective psychosis (N = 324) and paranoia (N = 93). kSchizophrenia, shizophreniform disorder, schizoaffective disorder, depression, dysthymia, mania, brief reactive psychosis, delusional disorder, alcohol or other drug abuse or de-pendence, or a personality disorder. lSchizophrenia, shizophreniform disorder, schizoaffective disorder, depression, dysthymia, mania, cyclothymia, delusional disorder, or other psychotic disorder. mIncluded generalized anxiety disorder, panic disorder, agoraphobia, social phobia, and simple phobia. nSchizophrenia (19%); major depression (34%); psychotic disorder (10%); others ( 37%). *Statistically different from the reference group at a p level of 0.01 or less.

Abbreviations: AF: Affective disorder; AX: Anxiety disorder; APD: Antisocial Personality Disorder; AUD; Alcohol Use Disorder; Ave: average; NA: Non Applicable; NI: Non Indicated; O-R: Odds Ratios; PD: Personality Disorder; SE: Socio-Economic status; SUD: Substance Use Disorder; SZ: Schizophrenia.



male outpatients with Sz only [25,32,35] (Table 1). With the aforementioned exception of the MacArthur data [4, 44], Sz is usually associated with similar [27,39] or higher violence risks than major depression or bipolar disorder, even without SUD [25,28,29,42,45,46] (Table 1). Further comparative investigations are needed to confirm this possibility.

What is the Proportion of Violence in the Community Attributable to Psychiatric Outpatients?

If one consensus exists presently, it is that very few out-patients with a MMD are seriously violent (Table 1). More than 90% of patients previously hospitalized for psychiatric disorders or persons with a severe mental disorder without prior hospitalization have never been violent [47] and as-ymptomatic patients with no history of violence are compa-rable to members of the general population in terms of vio-lence risk [48]. Clearly, only a minority of offenders is re-sponsible for the majority of violent acts associated with MMDs. Thus, as underlined in virtually all related studies, while the odds ratio for violence committed by persons with a MMD are significantly higher than those associated with the general population, the absolute number of violent acts attributable to severe mental illness in the community is very low (Table 1). According to the pioneer report of Swanson and colleagues [25], only 3% to 5% of community violence is attributable to severe psychiatric disorders [49] and it usu-ally take place in a private residence, often the family home (discussed below). Thus, 95% to 97% of violent acts would still be committed within a community where no resident would have received a diagnosis of MMD [12]. Under-standably, improved care of patients at risk of violence would not suffice to improve public security by a substantial measure. Other recent longitudinal investigations reported higher proportions of community violence related to MMDs however, reaching 15% to 20% [11,29], including 6% to 11% due to Sz [24, 28]. If these figures are confirmed, psy-chiatry could contribute significantly to reduction of this type of violence (e.g. [50,51,91]), even if it benefits more to family members and acquaintances of the patients than the general community.

Defining Subgroups of Psychiatric Outpatients on the Basis of Risk Factors

Individual, social, and environmental factors significantly influence the emergence of violence among persons with a MMD, just as they do among the general population [10]. One exception is the magnitude of gender difference. The enormous gap between the proportions of violent men and violent women in the general population tends to diminish among persons with a MMD, especially when wide ranges of violence are considered [52-55]. Physical assaults committed by women are more likely to occur during acute phase, within days surrounding hospital admission [53,56]. In the MacArthur study, prevalence of violence was similar for men and women outpatients, although women were less likely to provoke serious injury and they more frequently assaulted a family member, at home, than men [54].

Violence committed by men with a MMD, however, is highly heterogeneous and three subgroups of violent patients are currently defined that are associated with different risk factors (especially among men with Sz [10,13]). The first subgroup suffers from prominent neurological soft signs (or

brain damage), which underlie recurrent impul-sive/disorganized behaviors, commonly linked with chronic state and inpatient violence (e.g. [57,58]). Inpatient, chronic violence is more commonly influenced by immediate envi-ronmental factors, such as ward overcrowding or increased staff demands (e.g. [59,60]). This type of neurological vio-lence is not typically dangerous, often consisting of verbal threats or acts aimed at objects in response to frustration or agitation [60]. It is highly recidivistic, however, and difficult to predict. The second subgroup evidences acute positive psychotic symptoms, which might lead to more organized, serious, although isolated behaviors. While it is well estab-lished that psychotic manifestations do not generally lead to violent behavior (e.g. [61]), certain symptoms, especially persecutory delusions (see [86] for a review) and, perhaps, the related TCO triad (the belief to be in danger, the appre-hension of being harmed or the fear to be controlled by ex-ternal forces), might lead to violence [28,34,62-65,82]. These triggers seem to affect proportionally more women than man, although very few relevant data are available (e.g. [53]). In any event, violence recidivism in this subgroup is low given good medication response and compliance; family members are commonly involved; and the patient might pre-sent no prior evidence of aggression [66].

Finally, the third subgroup of violent persons with a MMD is characterized with factors classically associated with delinquency and violence among the general population (e.g. being a young male with low income, living in an un-derprivileged neighborhood and suffering from a SUD; e.g. [67]). Antecedent of violence, high scores on the psychopa-thy checklist and/or the presence of a comorbid APD diag-nosis might also be associated with recurrent community violence among persons with a MMD, particularly Sz [10,13,43,50,68,81]. In these cases, violence usually ante-dates the onset of the MMD; treatment compliance and fol-low-ups are difficult to obtain; recidivism is expected; and alcohol intake is frequently related to the assaults [10,69]. This type of violence is typically unplanned and independent of psychotic manifestations; it involves high proportions of friends or acquaintance, who consumed alcohol with the offender, usually a men [53,66]. Thus, it is crucial to deter-mine the history of violence in assessing the risks of aggres-sion, as the best predictor for future violence is past violence, both among the general and the psychiatric populations. In doing so, it should be kept in mind that relying solely on official records lead to markedly under-reporting of violence; officially, 4.5% of the patients in the MacArthur study have been violent during the follow-up year, while 23.7% ac-knowledged violence themselves [4]. Interestingly, the anti-social factor of the psychopathy Checklist was also corre-lated with higher risk of violence in the MacArthur study [6]. Monahan and colleagues [6] underscored the importance of the social context for violence committed by psychiatric out-patients and demonstrated that outpatients living in a highly underprivileged environment committed more violent acts than those living in less underprivileged neighborhoods (see also [67]). Thus, reduction of violence committed by psychi-atric outpatients does not depend solely upon psychiatric factors. It is important to conceptualize this violence as community violence in general, that is, by according careful attention to the context in which it occurs. In these cases,



history of violence constitutes the best better predictor of future violence.

Homicide and MMDs

Homicide, the most extreme expression of violence, rep-resents a particular case, as proportions of offenders with MMD, especially Sz, are particularly high among homicide offenders. Rates up to 10% of homicide male offenders are diagnosed with Sz in Europe and Australia [39,40,41,42,46, 70; see 23 for a review]. Thus, the occurrence of Sz is ap-proximately 10 times higher among homicide offenders than among the general population in these countries, and the odd ratios for homicide usually range from 7 to 10 for men with Sz. When alcohol abuse is present, the risks for homicide could increase by a multiple of 16 in men and of 84 in women with Sz [40]. Moreover, approximately 10% of men with Sz commit suicide (e.g. [71]). Depression, celibacy, male gender, unemployment, social isolation, and young age are associated with suicide among persons with Sz (e.g. [71]), just as they are among the general population. Wallace and colleagues [39] judiciously stressed that 99.97% of men with Sz involved in their study did not commit a homicide, for an approximate annual risk of only 1:3000. Still, the same rates for the Australian general population varied be-tween 1.0 and 1.4 for 100 000. Of course, homicide consti-tutes a very rare act, with rates ranging from 1 to 5 cases per 100,000 inhabitants per year in most industrialized countries, so that absolute numbers of homicides attributable to Sz are especially low (Table 1).

Victims and Locations of Assault Generated by Persons with MMDs

Public fears of being attacked randomly as a result of irrationality from a psychiatric outpatient are clearly un-founded. All available studies demonstrated that victims of assault are generally known to the patient (e.g. [72]). Most studies report that family members represent approximately 50% of the victims of violent psychiatric offenders [73-77]. When they are not relatives, victims usually had a personal (friend, acquaintance, roommate, neighbor, etc.) or profes-sional (e.g. health care providers, social workers, police offi-cers) relationship with the aggressor [66,76]. Total strangers generally account for only 12% to 16% of the cases [76,77,4,23,66]. However, the risk for assault of a nonrela-tive is increased when the psychotic offender is young, male, substance abuser, and does not live with his family [73,74,78]. With or without comorbid diagnoses (e.g. APD, SUD), violence related with MMDs usually take place at home and rarely in public places [4,66]. In the MacArthur study [4], victims included family members (51%), primarily the spouse, acquaintances or friends (35%), and complete strangers (14%). Two thirds of assaults occurred in private residences and less than one-third in public places. They occurred most often in the course of daily living activities or as part of an unpremeditated encounter. In only 13% of cases did patients plan their actions and actively seek out their vic-tims, and less than 10% presented active psychotic symp-toms at time of assault [6]. These results concord with the aforementioned finding [4] that anger and impulsiveness were more important than the presence of psychotic symp-toms as predictors of violence in that study. Once an outpa-tient is successfully followed, medication is administered,

and a stabilized state is reached, violence occurrence is low and would be more closely associated with impulsivity than psychosis.

Are There Protective Factors for Violence Among Per-sons with MMDs ?

Unfortunately, protective factors are still not the objects of rigorous investigations and they have essentially been identified through clinical practice. These include pro-social involvement, solid social support, strong attachment or rela-tional ties, a positive attitude towards authority, self-investment in academic training, and resilient personality traits [79]. Their presence does not reduce risk factors arith-metically, and a model has yet to be validated to account for their interactions.

One Notable Exception: The MacArthur Investigation

The well-known MacArthur study [6], a prospective, follow-up investigation involving more than 1000 psychiat-ric outpatients and 500 persons of the general population lead to the counterintuitive conclusion that without indica-tions of substance misuse, no difference exists between the prevalence of interpersonal violence perpetrated by the out-patients and their neighbors, especially when Sz was diagno-ses [4]. This conclusion seems at odd with all the abovemen-tioned studies and certain particularities deserve to be men-tioned. In the MacArthur investigation, violence prevalence among psychiatric outpatients without symptoms of sub-stance abuse disorder (SUD) was estimated every 10 weeks during a year (up to 5 times) and compared (for a subgroup of 336) with violence prevalence of the general population. When no symptoms of SUD were reported, 4.6% of the pa-tients on average have been violent at each follow-up, com-pared with 3.3% of their neighbors, which indeed is non-significant. However, as acknowledged by the authors, the 1-year aggregate of interpersonal violence among all outpa-tients without a SUD was considerably higher, at 17.9%. Although the comparable aggregate proportion of violent persons among the controls is unknown (they were only in-terviewed once), it would very unlikely approach 18%, even in this reputedly rough neighborhood and even for an entire year, especially when symptoms of substance misuse are absent (estimates of interpersonal violent persons in the gen-eral population usually approximate 2-3%, Table 1). This important discrepancy between the violence rates at each follow-up and the aggregate violent proportion suggests that different outpatients without symptoms of SUD were violent at different time of the follow-up. That is, each report of vio-lence did not simply concern the same recidivistic persons, as it would more likely be the case among the general popu-lation. Instead, for some patients violence seems to emerge later than others after discharge. Although this hypothesis of early vs late “bloomer” subgroups was not supported by semiparametric analyses conducted by Monahan and col-leagues [6] for the whole sample, it might concerns only assaulters without signs of substance misuse, whose curve of violence frequency was flat throughout the follow-up. Thus, it would be interesting to compare the year aggregate rates of violence for both groups (with and without a SUD) to clarify the picture.

Moreover, only 17.2% of the patients in the MacArthur study received a primary research diagnosis of Sz (with an



even lower 14.6% who were compared with the community sample, as opposed to 45.5% with a diagnosis of depression [4]). Because Sz is typically associated with higher risks for violence than either the absence of a psychiatric diagnosis or the presence of another MMD (e.g. see the Table 1; see also [12] for an excellent review), the aggregate prevalence of assaults could have been higher in the MacArthur study if more persons with Sz have accepted to participate to the study and followed at least 10 weeks. While superior rates of violence were found in association with major depression and bipolar disorder than Sz, the refusal rate for persons di-agnosed with Sz was significantly higher (43.7%) than that of persons receiving other diagnoses, as acknowledged by the investigators (e.g. major depression, 20.7%; [4,6]). Un-fortunately, significant proportions of outpatients who refuse to participate in longitudinal studies (or are lost during the follow-up) are at higher risk for repetitive community vio-lence and other antisocial behaviors (see also [18,81] for similar arguments). The risks of violence often decline in parallel with the severity of psychotic symptoms in tran-siently aggressive patients, who are more likely to pursue the follow-up and to comply with the medication than recidivis-tic violent outpatients with comorbid diagnoses [18]. It is worth noting, then, that participants with Sz who were lost during the study were significantly more likely to be violent (and not included in the analyses) than persons who were successfully followed in the MacArthur investigation, (as recognized by the authors [4,6]). Thus, it is difficult to con-clude from the MacArthur data that Sz is definitely not asso-ciated with elevated risks of community violence compared with the general population (or with lower risks than other MMDs). In spite of the abovementioned factors, 14.8% of persons with Sz in this study still reported at least one physi-cal aggression during the year [6]. And among persons with Sz who did not report violent fantasies during the hospitali-zation, 7.3% assaulted someone within the first 20 postdis-charge weeks [6]. The fact that these proportions were found exclusively among civilly, voluntary admitted patients, judged at lower risk for further violence (by virtue of their discharge) and more apt to comply with the medication (they were successfully followed for a year), renders these figures even more impressive.

The Link Between Psychotic Symptoms and Violence in the MacArthur Investigation

Data from the MacArthur also suggested that psychotic symptoms, including the notorious Threat-Control-Override (TCO) class ([82]; see above), do not have predictive value for subsequent violence when anger and impulsivity were controlled [5]. It is noteworthy that in this study, the ratings of psychotic symptoms were obtained after probing by inter-viewers and not simply based on the first responses of the patients [5]. However, important points are to be considered here, as it is typically difficult to interpret divergent findings from studies involving psychiatric outpatients. That study was based on a prospective design, which is excellent in general, except for the inevitable lack of time contiguity be-tween symptoms and violent acts, preventing the establish-ment of a link (causal or not) between delusions and vio-lence. More importantly, the rates of violence steadily de-creased throughout the prospective year of the investigation (13.5%, 10.3%, 6.9%, 7.6%, and 6.3% of violent patients at

each follow-up, respectively; 60% of assaults occurred in the 20 first weeks following hospital discharge), just as the pro-portions of reported delusions (28.9%, 16.7%, 16.1%, 14.0%, 12.1%, and 12.0% at each interview including the first in hospital; [5]). Thus, both factors (delusions and vio-lence) declined in parallel. As underlined elsewhere [17,83], this pattern suggests that risks for violence peak before, dur-ing, and shortly after hospitalization, when psychotic symp-toms are more severe. Within the first several weeks, given good treatment compliance and response, violence risks would subside (see also [36,84,85]). Accordingly, the role of medication was non-negligible in the MacArthur Study, as 25% of violent outpatients were not compliant at the time of assault [6]. For clinicians, these findings stress the impor-tance of offering tighter follow-up during this critical early period. Besides, the MacArthur study involved only a minor-ity of patients with Sz (although they are more likely to suf-fer from acute positive symptoms related with assaults), who were all voluntary admitted (inclusion of all psychiatric out-patients, including those in forensic settings would certainly generate different results), and who all received their dis-charge from hospital (considered at low risk for violence).

Interestingly, the emotional component of persecutory delusions might be crucial in triggering action (see [86] for a review). An increasing number of authors stress the impor-tance of negative affect and other distress factors such as low self-esteem, anxiety, anger, unhappiness and fear in increas-ing the risks that delusions would be acted upon [86-88]. In the MacArthur study, persecutory delusions at admission were significantly associated with negative affect and action during the previous 2 months, prompting the suggestion that delusional assaulters might act in response to the dysphoric aspect of their symptoms [89]. Overall, these results suggest that non-medicated persons with Sz (prior to hospital admis-sion), suffering from persecutory delusion and negative af-fect might be at higher risks for violence.

Psychotic manifestations could be important among fo-rensic populations as well (e.g. [90]). In a prospective study involving men with Sz discharged from forensic (71%) or general (29%) psychiatric settings, psychotic symptoms had predictive value for subsequent community violence (6 or 12 months later; [34]). Once an Antisocial Personality Disorder (APD) diagnosis, a high score on the psychopathy checklist and a Substance Use Disorder (SUD) diagnosis were con-trolled, the presence of a severe positive symptom increased the risk of aggressive behavior 4 to 5 times in this follow-up [34]. Thus, the combination of court-ordered community treatment and medication compliance would effectively lower the risk of violent behaviors [91].

CONCLUSION

Stating that most of the community violence is not com-mitted by mentally ill persons is a euphemism. An eventual national policy aiming the roots of violence should certainly not focus on MMDs. However, MMDs affect judgment, which, with the interruption or insufficiency of care, often leads to social isolation. In Montreal, for example, 30% of the itinerant persons have a severe psychiatric history, with a mean of 4 hospitalizations, the longest lasting 6 months [80]. Severe mental illness, in a manner that is yet obscure, has a singular bearing on the expression of an imbalance that is



violence. Crosscutting factors such as impulsivity are proba-bly at play regardless of diagnosis, underscoring the need for models that integrate both neurobiology and psychosocial fields [11]. As a first step, important risk factors for psychi-atric violence have been defined: history of violence; non-compliance with pharmacological and outpatient treatment substance abuse; violent ideation or fantasies; acute persecu-tory delusions with negative affect; and brain lesions. These various elements allow describing profiles of patients at risk. This approach should serve to better evaluate and to better target preventive and therapeutic interventions. However, the global interaction between these factors, including protective factors, is still unknown.

Compliance with treatment has repeatedly been found to be of utmost importance in regard with violence, including in the MacArthur study [6]. Accordingly, involuntary outpa-tient commitment combined with adherence to antipsychotic medication and absence of substance misuse have been found to lower the risk of violent behavior of patients with a MMD [91]. Finally, violence must always be situated within the context of a singular life course. The challenge for a cli-nician mindful of his patient is to distinguish between de-structive violence, which is unacceptable, and the hatred that inevitably accompanies the discovery of the difference with others. The latter merits empathy, although the risk remains of sliding imperceptibly, by virtue of a professional reflex, towards a denial of violence. Psychiatrists must exercise the utmost vigilance in this regard: Risk for violence should be topmost on their list of concerns. As privileged observers, they have the power to reduce the frequency of violent be-haviors by acting on the factors that fall within their field of competence. They can thus contribute to spare much need-less anguish to all the persons involved in such unfortunate events. Notwithstanding the integrated treatment of sub-stance abuse, clinical engagement seems to play a crucial role among all the possible means to be implemented with patients at highest risk for violence.

NOTE

A preliminary version of this study has been presented in part at the Société Médico-Psychologique Française, Paris, in May 2005.

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Received: October 12, 2006 Revised: November 28, 2006 Accepted: November 29, 2006


Major Mental Disorders and Violence: A Critical Update

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