Download The Correlates of Comorbid Antisocial Personality Disorder in

The Correlates of Comorbid Antisocial
Personality Disorder in Schizophrenia
by Paul Moran and Sheilagh Hodgins
cent of the men and 17 percent of the women with schizophrenia met criteria for DSM-III-R APD, in a sample of
male forensic patients with schizophrenia the prevalence
of APD was estimated to be 27 percent, and in a sample
of incarcerated offenders with schizophrenia the prevalence of APD was 63 percent (Hodgins et al. 1996).
APD indexes a pattern of antisocial behavior that
emerges early in life and that remains stable across the
life span. The diagnosis is given when an individual presents a "pervasive pattern of disregard for and violation of
the rights of others occurring since age 15 years" (APA
1994, p. 649) and behaviors present before age 15 that
meet criteria for a diagnosis of conduct disorder as indicated by "a repetitive and persistent pattern of behavior in
which the rights of others or major age-appropriate societal norms or rules are violated" (APA 1994, p. 90). Data
from the ECA Study indicate that the risk of schizophrenia increases in a linear fashion with the number of conduct disorder symptoms (Robins and Price 1991).
Furthermore, a prospective investigation of a New
Zealand birth cohort revealed that 40 percent of the
cohort members who developed schizophreniform disorders by age 26 presented conduct disorder as children
and/or adolescents (Kim-Cohen et al. 2003). Consistent
with these findings are the results of prospective studies
of children at high risk for schizophrenia (by virtue of
having a mother with the disorder) that have identified a
subgroup of boys with behavior problems (Asarnow
1988). In the Copenhagen High-Risk project, it was boys
with behavior problems who developed predominately
positive-symptom schizophrenia (Cannon et al. 1990).
Findings from other prospective investigations (see, e.g.,
Hodgins and Janson 2002) and several retrospective studies of clinical samples of men with schizophrenia confirm
that a subgroup of males who develop schizophrenia dis-
Abstract
More than 15 years ago, findings from the
Epidemiological Catchment Area Study indicated that
antisocial personality disorder (APD) is more prevalent among persons with schizophrenia than in the
general population. The present study analyzed data
from a multisite investigation to examine the correlates of APD among 232 men with schizophrenic disorders, three-quarters of whom had committed at least
one crime. Comparisons of the men with and without
APD revealed no differences in the course or symptomatology of schizophrenia. By contrast, multivariate
models confirmed strong associations of comorbid
APD with substance abuse, attention/concentration
problems, and poor academic performance in childhood; and in adulthood with alcohol abuse or dependence and deficient affective experience (a personality
style indexed by lack of remorse or guilt, shallow
affect, lack of empathy, and failure to accept responsibility for one's own actions). At first admission, men
with schizophrenia and APD presented a long history
of antisocial behavior that included nonviolent offending and substance misuse, and an emotional dysfunction that is thought to increase the risk of violence
toward others. Specific treatments and management
strategies are indicated.
Keywords: Schizophrenia, antisocial personality
disorder, treatment, prevention, etiology.
Schizophrenia Bulletin, 30(4):791-802, 2004.
The prevalence of antisocial personality disorder (APD)
is elevated among men and women with schizophrenia as
compared to the general population. The Epidemiological
Catchment Area (ECA) Study revealed that the prevalence of schizophrenia was 6.9 times higher among men
with APD and 11.8 times higher among women with APD
than among men and women generally (Robins et al.
1991; Robins 1993). Other studies have confirmed these
findings. For example, in a community sample, 23 per-
Send reprint requests to Professor S. Hodgins, Box PO23, Department
of Forensic Mental Health Science, Institute of Psychiatry, De Crespigny
Park, Denmark Hill, London SE5 8AF; e-mail: [email protected].
791
Schizophrenia Bulletin, Vol. 30, No. 4, 2004
P. Moran and S. Hodgins
play a pattern of antisocial behavior both before and after
the onset of schizophrenia (Hodgins 2004).
Comorbid APD amplifies the suffering of people with
schizophrenia. Among men with schizophrenia, comorbid
APD is associated with persistent criminality, much of it
nonviolent, that begins in adolescence and often leads to
imprisonment (Hodgins and Cote 1993), with early-onset
substance use, unemployment, and homelessness
(Tengstrom and Hodgins 2002). Other studies suggest that
the presence of APD among persons with schizophrenia is
associated with an increased severity of substance abuse,
a greater severity of symptoms of psychosis, higher rates
of police contact, and with violent behavior (Mueser et al.
1997, 1999; Gandhi et al. 2001; Moran et al. 2003).
Furthermore, a small number of studies have reported that
the presence of comorbid APD is associated with poor
outcome for the treatment of schizophrenia (Torgalsb0en
1999; Tyrer and Simmonds 2003). The lack of studies of
the impact of comorbid APD on response to treatment and
outcome in schizophrenia is surprising. This lack may
result, at least in part, from the reluctance of individuals
with both of these disorders to participate in research
(Hodgins et al., in press). Such patients pose enormous
difficulties to clinical services, as they fail to comply with
treatment and persist in using drugs and alcohol.
The association between schizophrenia and APD may
also have important implications for understanding the
etiology of schizophrenia. For example, consider the evidence on hereditary factors for schizophrenia and for
APD. One hypothesis suggests that genetic factors associated with schizophrenia confer vulnerability for antisocial
behavior. This hypothesis is supported by findings from
family studies demonstrating an elevated prevalence of
antisocial behavior and criminality among relatives of
persons with schizophrenia (Silverton 1985; Kay 1990)
and by the results of two adoption studies showing that
schizophrenia in the parental generation increases the risk
of criminality among the offspring (Heston 1966;
Silverton 1985). An alternative hypothesis suggests that
individuals with schizophrenia and APD have inherited a
vulnerability for externalizing problems that includes substance abuse. A recent meta-analysis of twin and adoption
studies estimated the heritability of externalizing problems at 0.41 (Rhee and Waldman 2002). Children vulnerable for schizophrenia who carry the low-activity variant of
the functional polymorphism in the gene encoding
monoamine oxidase A genotype could develop stable antisocial behavior as a result of an interaction between this
hereditary factor and severe child abuse (Caspi et al.
2002). It has been reported that individuals with schizophrenia spectrum disorders mate disproportionately with
antisocial individuals (Parnas 1988). This could be
another way in which children inherit one set of genes
conferring a vulnerability for schizophrenia spectrum dis-
orders and another set conferring a vulnerability for externalizing problems. Just as investigations of hereditary factors associated with schizophrenia have not taken account
of antisocial behavior patterns, studies of the role of
obstetric complications have not taken account, for example, of the damage that maternal antisocial behavior could
do to the developing fetus.
Some children with conduct disorder (Frick et al.
2003) and some adults with APD (Cooke and Michie
1997) also display two personality traits included in the
syndrome of psychopathy: arrogant and deceitful interpersonal conduct, and deficient affective experience. The first
trait does not characterize men with schizophrenia, but
deficient affective experience is elevated among offenders
with schizophrenia (Tengstrom and Hodgins 2002) and
overlaps with negative symptoms. It includes four items:
lack of remorse or guilt, shallow affect, lack of empathy,
and failure to accept responsibility for one's own actions.
It is hypothesized that this trait emerges early in life, contributes to the initiation and maintenance of antisocial
behavior, and is associated with repetitive violence
(Cooke and Michie 1997; Blair 2003).
In summary, there is compelling evidence of an association between schizophrenia and APD and of the harmful consequences for individuals afflicted with both disorders. This association has been the focus of comparatively
little research, and the available findings suggest that it
may have implications for treatment provision and etiology. The present study was a secondary analysis of data
collected from the Comparative Study of the Prevention
of Crime and Violence by Mentally 111 Persons (Hodgins
et al., in press). The sample included 232 men with schizophrenia who were extensively assessed at discharge from
either a general psychiatric hospital or a forensic psychiatric hospital in one of four sites. These men were
recruited into a multisite study of community treatment.
The four sites (southern British Columbia, Canada;
Finland; the state of Hessen in Germany; and southern
Sweden) were selected because they all included large
catchment areas in which the centralized forensic services
treated almost all, if not all, mentally ill persons prosecuted for a criminal offense. The aim of the study was to
identify characteristics of persons with schizophrenia and
APD that may be of relevance for treatment and service
provision, the prevention of criminal behavior, and the etiology of these associated disorders.
Method
Sample. The sample included 232 men with schizophrenia who had been discharged from either a general psychiatric hospital or a forensic psychiatric hospital in four
sites (southern British Columbia, Canada; Finland; the
792
Comorbid Antisocial Personality Disorder
Schizophrenia Bulletin, Vol. 30, No. 4, 2004
state of Hessen in Germany; and southern Sweden). One
hundred and forty-five (62.5%) of the men had been discharged from a forensic psychiatric hospital, and 87
(37.5%) had been discharged from a general psychiatric
hospital. The proportion of the total sample recruited in
each site was as follows: Canada, 39 percent (n - 90);
Finland, 25 percent (n = 57); Germany, 27 percent (n =
63); and Sweden, 9 percent (n = 22). The mean age of the
sample was 38 years (standard deviation [SD] = 11.3), and
the principal DSM-IV (APA 1994) diagnoses were schizophrenia (n = 186), schizoaffective disorder (n = 45), and
schizophreniform disorder (n = 1). Twenty-two percent of
the total sample (n = 51) (95% confidence interval [CI]:
16.7-27.3) met DSM-FV criteria for a comorbid diagnosis
of APD: 26 percent (n - 38) of the forensic patients and 15
percent (n = 13) of the general psychiatric patients. In
addition, 57 percent (n = 132) (95% CI: 50.5-60.3) of the
sample had a diagnosis of alcohol abuse and/or dependence, and 44 percent (n = 101) (95% CI: 37.2^9.9) of
the sample had a diagnosis of drug abuse and/or dependence. Psychosocial functioning was low; the mean score
on the Global Assessment of Functioning Scale (GAF;
Spitzer et al. 1992) for the sample was 49.3 (SD = 13.0),
and 60 percent (n = 139) had never had an intimate relationship. The mean age at first admission to the hospital
was 24.8 years (SD = 8.8), and the mean number of admissions was 8.0 (SD = 7.1). Three-quarters (n = 173) of these
men had been convicted of at least one crime: 99 percent
(n - 143) of the forensic patients and 34 percent (n = 30)
of the general psychiatric patients. There were 38 participants (16%) who had committed at least one homicide or
attempted homicide and all were recruited from a forensic
hospital. The mean total number of crimes in the entire
sample was 9.9 (SD = 19.2), and the mean total number of
violent crimes was 2.6 (SD = 5.0).
childhood and adolescence (defined as birth to age 18)
was obtained from participants; family members; and
school, military, criminal, and medical files. A consensus
decision about each variable was made by the research
psychiatrist and research assistant after all information
had been extracted from files and interviews with patients
and family members had been completed.
Parents' characteristics. Information on parents
was obtained from the participants, family members, and
in some cases records.
Diagnoses. Primary, secondary, and tertiary diagnoses—lifetime and current—were made using the
Structured Clinical Interview for DSM-IV (SCID) for
Axis I and II disorders (Spitzer et al. 1992). Experienced
psychiatrists who were trained by the developers of the
instrument administered the SCID. The psychiatrists in
the four sites all spoke English and were trained and
tested using videotaped interviews with patients speaking
English. Information from participants; family members;
school, medical, and social service records; and treatment
staff was used to make diagnoses. The use of multiple
sources of information was particularly important to corroborate and confirm the diagnosis of conduct disorder.
Interrater reliabilities calculated on 38 cases reached K =
1.0 for the principal diagnosis of schizophrenia and K =
0.85 for APD.
Psychosocial functioning. Psychosocial functioning
was indexed by four variables. Psychiatrists who administered the SCID assessed psychosocial functioning in the 6
months prior to discharge using the GAF. Interrater reliabilities calculated on 33 cases were estimated at K = 0.61.
Information about intimate relationships, employment history, and compulsory military service (for the Finnish,
German, and Swedish participants) was obtained from
participants, family members, and official records.
Symptoms. Psychotic symptoms were assessed
using the Positive and Negative Syndrome Scale (Kay et
al. 1987). Interrater agreement, calculated on 37 cases,
reached K = 0.70 for positive symptoms and K = 0.52 for
negative symptoms.
Personality. Trained research psychiatrists assessed
psychopathic traits using the
Psychopathy
Checklist-Revised (PCL-R; Hare 1991). Three factor
scores, as described by Cooke and Michie (2001), were
calculated: (1) arrogant and deceitful interpersonal conduct (items 1, 2, 4, and 5); (2) deficient affective experience (items 6-8, and 16); and (3) an impulsive and irresponsible behavioral style (items 3, 9, and 13-15).
Interrater agreement, calculated on 38 cases, ranged from
K = 0.85 for the total scores, to K = 0.75 for arrogant and
deceitful interpersonal conduct, K = 0.75 for deficient
affective experience, and K = 0.89 for impulsive and irresponsible behavioral style.
Measures
Sociodemographic information. Information on
sociodemographic characteristics was collected from the
participant, family members, and medical files.
History of psychiatric treatment. Information on
previous psychiatric treatment was extracted from hospital files.
Criminality. Information on criminality was
extracted from official criminal records. Throughout this
article, the term convictions is used broadly to include
judgments of nonresponsibility due to a mental disorder.
Violent crimes are defined as all offenses causing physical
harm, threat of violence or harassment, all types of sexual
offenses, illegal possession of firearms or explosives, all
types of forcible confinement, arson, and robbery. All
other crimes are defined as nonviolent.
Childhood and adolescent history of antisocial
behavior and academic performance. Information on
793
Schizophrenia Bulletin, Vol. 30, No. 4, 2004
P. Moran and S. Hodgins
Procedure. Within each site, each participant with a
diagnosis of a major mental disorder being discharged
from the forensic hospital was approached and invited to
participate in the study. If the participant formally consented to participate, the SCID (Spitzer et al. 1992) was
completed. If a diagnosis of a major mental disorder was
confirmed, the participant was included in the study and
the other interviews and assessments were completed and
information was collected from files and collaterals.
Patients from general psychiatric hospitals in the same
geographical region who had the same sex, similar age
(±5 years), and the same principal diagnosis were identified and also invited to participate in the study. If the principal diagnosis was confirmed by the research psychiatrist
using the SCID, the same information was collected as for
the other participants.
APD, compared to those without APD, met criteria for
alcohol and drug abuse or dependence. The history of
treatment in psychiatric services, psychosocial functioning, and symptoms at discharge did not distinguish those
with APD. As would be expected because of the overlap
between symptoms of APD and items on the PCL-R, the
participants with APD obtained higher mean total PCL-R
scores and higher scores on the factor indicating an
impulsive and irresponsible behavioral style. Notably,
however, they also obtained higher scores on the trait of
deficient affective experience, which does not overlap
with APD symptoms. The statistical significance of this
comparison, however, diminished after applying the
Bonferroni correction.
Childhood
and
Adolescent
Characteristics.
Comparisons of childhood and adolescent characteristics
of participants with and without comorbid APD are displayed in table 1. Participants with APD, as compared to
those without, were significantly more likely to have
experienced attention and concentration problems. While
82 percent of the men with APD abused substances before
age 18, so did 41 percent of those without APD. The academic performance of the participants with APD was
poorer than that of participants without APD, as early as
elementary school, and a significantly greater number of
participants with APD had been placed in an institution
before 18 years of age. A number of other comparisons
were initially statistically significant at the 5 percent level,
but the differences failed to meet significance after the
Bonferroni correction was applied: earlier onset of symptoms of hyperactivity, depression, and substance misuse;
noncompletion of high school education; physical abuse
before age 12 years; paternal criminality; and paternal
substance abuse. No comparisons of criminality, substance abuse, and mental illness among the mothers and
siblings were statistically significant.
Data Analysis. All analyses were performed using Stata
version 7 (StataCorp 2001). Univariate associations
between a DSM-IV diagnosis of comorbid APD and all
baseline variables were examined using chi-square tests
and, where appropriate, the Fisher exact test for categorical variables and t tests for continuous variables. A
Bonferroni correction was applied to account for the use
of multiple statistical tests (p = 0.001). Three multivariate
models of childhood, adult, and adult criminal correlates
of comorbid APD were then determined using forward
stepwise logistic regression. To ensure that models were
based on exactly the same data, participants with missing
values for relevant variables were excluded before modeling. Each model started with the variables that were most
significantly associated with comorbid APD at a univariate level. Subsequent variables were then added and likelihood ratio tests were used to determine the significance
of adding the new variables to the model. Significant predictors from the childhood/adolescent model and the adult
model were then entered into a series of models, to identify the variables that most parsimoniously predicted
comorbid APD.
History of Criminal Offending. As displayed in table 1,
compared to men without APD, participants with APD
committed a significantly greater total number of crimes,
committed a significantly greater number of nonviolent
crimes, and were more likely to have committed a crime
before their first admission to general psychiatric services.
Notably, neither the mean number of violent crimes nor
the proportion of participants in each group who had committed a homicide differed.
Results
There was no difference in the mean age at entry into the
study or the parental occupational status of men with
comorbid APD compared to those without comorbid APD
(table 1).
Adult Mental Disorders, Cognitive Functioning, and
Personality. The men with and without comorbid APD
did not significantly differ with regard to principal diagnoses, the ages at onset of the prodrome or psychotic
symptoms, or the mean number of positive and negative
symptoms. A significantly greater proportion of men with
Multivariate Models. The first model included the childhood and adolescent variables that significantly distinguished the participants with and without comorbid APD.
The analysis included 221 participants with complete
data. Four predictor variables were entered into this
794
Schizophrenia Bulletin, Vol. 30, No. 4, 2004
Comorbid Antisocial Personality Disorder
Table 1. Comparisons of the characteristics of men with schizophrenia and schizoaffective disorder with and
without comorbid APD
Variable
Sociodemographic characteristics
Mean age (yrs)
Father's occupation
White collar or professional
Mother's occupation
White collar or professional
APD
No APD
Test
P
37.5 (SD= 11.7)
38.3 (SD= 11.2)
4230, n = 232) = 0.5
0.06
16% (7)
30% (47)
X 2 (1,n= 199) = 3.6
0.06
15% (7)
19% (31)
X 2 (1,n=207) = 0.4
0.05
78% (40)
20% (10)
2%(1)
19.0 (SD = 5.6)
22.3 (SD = 7.9)
81%
19%
—
20.3
24.1
(146)
(35)
X2(2, n = 232) = 3.6
0.2
(SD= 6.7)
(SD = 7.7)
498, n = 100) =-0.9
4193, n = 195) = 1.3
0.4
0.2
23.1 (SD = 7.8)
9.1 (SD = 8.6)
25.3 (SD = 9.0)
7.7 (SD = 6.6)
4230, n = 232) = 1.6
4230, n = 232) = 1.2
0.1
0.2
2.1 (SD= 1.9)
2.1 (SD = 2.1)
t(225, n = 227) = 0.2
0.9
3.9 (SD = 2.3)
3.8 (SD = 2.3)
4225, n = 227) =-0.1
0.9
77% (39)
65% (33)
5 1 % (93)
38% (68)
X 2 (1,n = 232) = 10.2
X 2 1 , n = 232 =11.9
0.001*
0.001*
Psychiatric history
Had made a previous suicide attempt
55% (28)
Mean total length of stay in hospital (mos) 12.9 (SD = 14.7)
Mean no. of involuntary admissions
4.2 (SD = 6.1)
49% (88)
12.1 (SD = 20.4)
2.9 (SD = 3.4)
x 2 0 . n = 232) = 0.6
4230, n = 232) = -0.2
4230, n = 232) = -2.0
0.4
0.8
0.05
Psychosocial functioning
Mean raw score GAF scale
Successfully completed military service
Employed at least once
Has had couple relationship
48.7
22%
86%
39%
49.5
25%
93%
40%
4223, n = 225) = 0.4
x2(2, n = 230) = 0.3
x 2 0 . " = 232) = 2.7
x 2 0 . n = 232) = 0.02
0.7
0.9
0.1
0.9
IQ
Mean global IQ
Mean verbal IQ
Mean performance IQ
89.6 (SD= 12.9)
86.7 (SD = 12.6)
91.0(SD = 14.7)
91.8 (SD = 15.9)
93.4 (SD= 15.5)
89.7 (SD = 17.5)
4174, n = 176) = 0.7
4165, n = 167) = 2.2
4164, n= 166) =-0.4
0.5
0.03
0.7
19.0 (SD = 6.7)
11.9 (SD = 7.4)
4228, n = 230)= -6.1
<0.001*
2.2(SD = 2.1)
4.4 (SD = 2.2)
1.6(SD=1.7)
3.3 (SD = 2.2)
4228, n = 230) = -1.9
4228, n = 230) = -3.0
0.06
0.003
5.7 (SD = 2.3)
4.0(SD = 2.6)
4228, n = 230) = -4.2
<0.001*
73% (37)
8.1 (SD = 3.6)
35% (18)
4.8 (SD = 2.9)
3 1 % (15)
8.5 (SD = 4.8)
38% (68)
9.4(SD = 4.1)
23% (40)
8.6 (SD = 4.3)
30% (53)
11.7 (SD = 4.4)
X 2 (1,n = 228)= 18.6
481, n = 83) = 1.6
X 2 (1,n = 228) = 3.4
436, n = 38) = 3.2
X 2 (1,n = 226) = 0.01
459, n = 61) = 2.5
<0.001*
0.1
0.1
0.003
0.9
0.01
Diagnoses
Principle diagnosis
Schizophrenia
Schizoaffective disorder
Schizophreniform
Mean age of onset of prodrome (yrs)
Mean age of onset of psychotic
symptoms (yrs)
Mean age of first hospitalization (yrs)
Mean no. of admissions to hospital
Symptoms
Mean no. of positive symptoms rated 3
or more on PANSS
Mean no. of negative symptoms rated 3
or more on PANSS
Comorbid diagnosis
Alcohol abuse or dependence
Drug abuse or dependence
Personality traits
Mean PCL-R total score
Mean score arrogant and deceitful
interpersonal behavior
Mean score deficient affective experience
Mean score impulsive and irresponsible
behavioral style
Symptoms before age 18 yrs
Attention/concentration problems
Mean age of onset (yrs)
Hyperactivity
Mean age of onset (yrs)
Depressive symptoms
Mean age of onset (yrs)
(SD = 14.4)
(11)
(44)
(20)
795
(SD = 12.6)
(45)
(169)
(73)
P. Moran and S. Hodgins
Schizophrenia Bulletin, Vol. 30, No. 4, 2004
Table 1. Comparisons of the characteristics of men with schizophrenia and schizoaffective disorder with and
without comorbid APD—Continued
Variable
Substance abuse
Mean age of onset (yrs)
Anxiety problems
Mean age of onset (yrs)
APD
No APD
Test
P
2
82% (41)
13.7 (SD = 2.5)
35% (17)
9.8 (SD = 5.6)
4 1 % (73)
14.9 (SD = 2.9)
34% (60)
9.7 (SD = 4.3)
X (1,n= 230) = 26.9
/(93, n = 95) = 2.0
X 2 (1,n = 226) = 0.01
/(59, n = 61) = 0.03
<0.001*
0.05
0.9
0.9
Childhood academic performance
Below average performance, elementary
school
Successfully completed high school
Placed in an institution before age 18 yrs
48% (24)
16% (8)
49% (25)
2 1 % (36)
40% (69)
24% (43)
X 2 (1,n= 224) = 14.8
X 2 (1, n = 222) = 9.9
X 2 (1,n = 229) = 11.7
<0.001*
0.002
<0.001*
Childhood victimization
Physical abuse before 12 yrs
Physical abuse after 12 yrs
Childhood sexual abuse
Witnessed parental violence
79%
50%
21%
23%
56%
38%
19%
23%
X 2 (1,n
X 2 (1,n
X 2 (1,n
X 2 (1,n
Paternal history
Father with criminal record
Father committed violent crime
18% (8)
9% (4)
6% (10)
1%(1)
X 2 (1,n = 201) = 5.9
Fisher's exact test
0.02
Father with substance abuse
46% (21)
3 1 % (50)
(n=198)
X 2 (1,n = 210) = 3.7
0.01
0.05
88% (45)
17.0 (SD = 8.4)
75% (27)
7 1 % (128)
18.7 (SD = 14.6)
36% (40)
X 2 (1, n = 232) = 6.4
/(230, n = 232) = 1.1
X 2 (1,n= 146) = 16.3
0.01
0.3
<0.001*
23.3 (SD = 30.0)
5.1 (SD = 8.6)
17.7 (SD = 26.9)
12% (6)
6.1 (SD = 12.53)
1.9(SD = 3.0)
4.0 (SD = 10.6)
18% (32)
t(230, n = 232) = -6.0
t{230, n = 232) = 2.6
/(230, n = 232) = 3.6
X 2 (1,n = 232) = 1.0
<0.001*
0.01
0.001*
0.3
Criminal history
Convicted of one or more crimes
Mean age of first judgment (yrs)
Crime before first admission to general
psychiatry
Mean total no. of crimes
Mean total no. of violent crimes
Mean total no. of nonviolent crimes
At least one judgment for homicide
(38)
(24)
(10)
(14)
(97)
(66)
(31)
(40)
= 220)
= 221)
= 214)
= 217)
=
=
=
=
8.2
2.2
0.2
1.0
0.004
0.1
0.7
0.3
Note.—APD = antisocial personality disorder; GAF = Global Assessment of Functioning; PANSS = Positive and Negative Syndrome
Scale; PCL-R = Psychopathy Checklist-Revised; SD = standard deviation.
* Significant association at p = 0.05 after Bonferroni correction for multiple comparisons.
model: attention/concentration problems, substance abuse,
below-average performance at elementary school, and
being placed in an institution before age 18. Likelihood
ratio tests indicated that the best model of childhood correlates of APD included three variables: attention/concentration problems before age 18 (adjusted odds ratio: 2.83;
95% CI 1.34-5.94); substance abuse before age 18
(adjusted odds ratio: 5.44; 95% CI 2.41-12.28); and
below-average performance at elementary school
(adjusted odds ratio: 2.91; 95% CI 1.39-6.11). This model
could not be improved upon to a statistically significant
degree by the addition of further variables and yielded an
overall likelihood ratio statistic of 46.96 (p < 0.001). The
three significant variables often co-occur; therefore, we
examined the proportions of participants characterized by
these variables. Among the men with comorbid APD, 32
percent were characterized by all three variables; 40 percent were characterized by two variables; 26 percent by
one variable; and 2 percent by none of the three variables.
The second model included variables that distinguished the participants with and without comorbid APD
in adulthood. The analysis included 230 participants with
complete data. Lifetime DSM-IV diagnoses of alcohol
abuse or dependence and drug abuse or dependence were
entered as predictors because they had significantly distinguished the participants with and without comorbid APD
in univariate analyses. While the total PCL-R scores and
the scores for impulsive and irresponsible behavioral style
were significantly different for the participants with and
without APD, they were not entered into the model
because they overlap with a diagnosis of APD. The score
for deficient affective experience may be important in
796
Comorbid Antisocial Personality Disorder
Schizophrenia Bulletin, Vol. 30, No. 4, 2004
understanding antisocial behavior among persons with
schizophrenia. It was therefore entered into the model
even though the univariate comparison was not significant
once the Bonferroni correction was applied. Site of
recruitment and hospital at discharge (forensic or general)
were also entered as covariates. The best model of adult
clinical correlates of APD included three variables: adult
alcohol abuse or dependence (adjusted odds ratio: 2.92;
95% CI 1.38-6.15); adult drug abuse or dependence
(adjusted odds ratio: 2.39; 95% CI 1.21^.72); and deficient affective experience (adjusted odds ratio: 1.25; 95%
CI 1.07-1.46). This model could not be improved upon to
a statistically significant degree by the addition of any further variables and yielded an overall likelihood ratio statistic of 27.8 (p < 0.001). Notably, among the participants
with schizophrenia and co-occurring APD, 37 percent
were characterized by all three variables; 41 percent were
characterized by two; 18 percent by one; and 4 percent by
none of the variables.
A final parsimonious model was determined (table 2).
This analysis included 220 participants with complete
data. The following variables were entered into this
model: attention/concentration problems before age 18,
substance abuse before age 18, below-average performance at elementary school, DSM-IV lifetime diagnoses of
alcohol abuse or dependence and drug abuse or dependence, deficient affective experience, site of recruitment,
and type of discharge. The most parsimonious model of
comorbid APD included five predictor variables: substance abuse before age 18, below-average performance at
elementary school, attention/concentration problems
before age 18, adult alcohol abuse or dependence, and
deficient affective experience. The model could not be
improved upon to a statistically significant degree by the
addition of further variables and yielded an overall likelihood ratio statistic of 56.2 (p < 0.001). As with the previous multivariate models, many of the participants with
comorbid APD were characterized by the co-occurrence
of several of these variables. Among the men with comor-
bid APD, 14 percent were characterized by all five predictors, 44 percent by four, 22 percent by three, 18 percent
by two, and 2 percent by one.
Finally, a model was determined using variables
descriptive of participants' criminal careers. The following variables were entered into this model: total number
of crimes, total number of violent crimes, total number of
nonviolent crimes, having a criminal conviction before
first admission to general psychiatry, site of recruitment,
and type of discharge. The best model of criminal correlates included only two variables: total number of crimes
(adjusted odds ratio: 1.03; 95% CI 1.01-1.05) and having
a criminal conviction before first admission to general
psychiatry (adjusted odds ratio: 3.13; 95% CI 1.23-7.94).
Discussion
Among this large sample of men with schizophrenia,
those with and without comorbid APD did not differ in
their mean age at onset of prodrome, mean age at onset of
psychosis, or levels of positive and negative symptoms at
discharge. Furthermore, their history of treatment did not
differ; mean age at first admission, average number of
inpatient stays, and total length of all admissions were
similar for the two groups. These findings support results
from previous studies (Hodgins et al. 1996, 1998;
Hodgins 2000; Tengstrom and Hodgins 2002).
While neither the schizophrenic disorder, nor timing
and length of hospital care, differed for men with and
without APD, criminality did differ. Those with APD, as
compared to those without, committed more nonviolent
criminal offenses, and significantly more of them began
offending before their first admission to a psychiatric
ward. This finding supports results from previous studies
of offenders with schizophrenia, indicating that the criminal careers of those with APD begin before first admission
to psychiatric service and involve primarily nonviolent
offending (Tengstrom et al. 2001; Hodgins and Janson
2002; Hodgins 2004). Notably, neither violent offending
Table 2. Multivariate model of best predictors of comorbid APD1
Variable
Odds ratio (95% CI)
p value
Substance abuse before age 18
4.48(1.93-10.42)
<0.001
Below-average performance at elementary school
2.85(1.33-6.11)
0.007
Attention/concentration problems before age 18
2.70(1.25-5.78)
0.01
Adult alcohol abuse or dependence
2.78(1.23-6.28)
0.01
Deficient affective experience
1.18(1.00-1.40)
0.05
Note.—APD = antisocial personality disorder; CI = confidence interval.
1
All odds ratios are adjusted for the effects of other variables in the model.
797
Schizophrenia Bulletin, Vol. 30, No. 4, 2004
P. Moran and S. Hodgins
nor homicide was found to be associated with APD. This
finding is consistent with the observation that there are
several distinct subgroups of offenders with schizophrenia
(Hodgins 2004).
The men who developed comorbid APD had experienced numerous difficulties in childhood and early adolescence. In addition to presenting conduct disorder, a significantly greater proportion of those with APD, compared
to those without APD, presented attention/concentration
problems in childhood and poor academic performance as
early as elementary school. Neither of these symptoms is
included in the diagnosis of conduct disorder. While truancy from school is a symptom of conduct disorder, it is
more common among teenagers than among elementary
school children and is not usually the cause of poor performance in elementary school. In our view, the poor
early academic performance of this group is related to a
combination of factors, including behavior problems,
attention and concentration difficulties, and low verbal
IQ. Low verbal IQ has been found to characterize children
who develop conduct disorder (Moffitt and Caspi 2001).
In addition, before the age of 18, a greater proportion of
the men with APD had spent time in an institution, had
been physically abused, and had fathers who had criminal
careers and who abused alcohol and drugs. The significance of some of these associations diminished after the
Bonferroni correction was applied, perhaps as a result of
insufficient sample size. However, these trends suggest
that boys developing both schizophrenia and APD experience multiple problems compounded by an adverse family situation. Given the implications of the findings from
the present study, replications with larger samples and
prospectively collected data are warranted.
Results from the present study highlight the need for
early childhood interventions to reduce antisocial behavior and to improve academic performance, family relationships, and parenting practices for children and adolescents at risk for schizophrenia. While interventions for
reducing childhood conduct problems have been shown to
be effective (Scott et al. 2001), the impact on children
with conduct problems who are at risk for schizophrenia
is unknown. Eliminating conduct problems among children vulnerable for schizophrenia could prevent future
criminality and substance misuse, provide them with
skills to cope with schizophrenia if it does develop, and
could possibly reduce the likelihood of developing schizophrenia.
Conduct-disordered children are exposed to alcohol
and drugs at an earlier age than other children and go on
to develop more enduring and severe substance abuse
problems (Robins and McEvoy 1990; Armstrong and
Costello 2002). In light of the recent evidence showing
that heavy cannabis abuse during adolescence increases
the risk of schizophrenia (Arseneault et al. 2002; Zammit
et al. 2002), intervening to reduce conduct disorder
among children with a family history of schizophrenia
spectrum disorders could reduce cannabis abuse and
thereby lower their risk of developing schizophrenia. The
effective treatment of conduct disorder during childhood
would reduce antisocial behaviors and increase prosocial
skills. If schizophrenia did develop, these skills might
serve to increase compliance with treatment and prevent
substance misuse and crime. While the effective treatment
of conduct disorder among children with a family history
of schizophrenia would appear to have many benefits,
treatment for childhood attention and concentration problems is potentially problematic. Stimulant medications
could theoretically alter an already fragile dopaminergic
system and increase the risk of later psychoses.
Preventing the development of APD in general, and
specifically among persons who develop schizophrenia, is
a goal worth striving toward. APD is almost always
accompanied by substance abuse, and this interferes with
treatments for both schizophrenia and antisocial behavior
(Buhler et al. 2002; Hunt et al. 2002). Recent evidence
also suggests that substance abuse may lead to more
severe brain damage among men with schizophrenia as
compared to those without (Mathalon et al. 2003).
The men with schizophrenia and comorbid APD
obtained higher ratings on the trait of deficient affective
experience than the men without APD. This trait has been
found to be associated with repeated violence toward others
(Cooke and Michie 1997; Blair 2003). Animal research has
shown that the recognition of distress in potential victims
limits aggressive behavior. Individuals who obtain high
scores for deficient affective experience are thus unrestrained because they fail to empathize with those they hurt.
While this trait is hypothesized to be the core of the syndrome of psychopathy (Cooke and Michie 1997; Blair
2003), it may also occur in conjunction with schizophrenia.
The results of the present study have implications for
both clinicians and researchers. Men with schizophrenia
and comorbid APD require specific interventions not only
to ensure compliance with treatment for schizophrenia but
also to reduce antisocial behavior and substance abuse
and to develop prosocial skills (Hodgins and MiillerIsberner 2000). Specific cognitive-behavioral programs
have been found to be effective in reducing offending and
increasing prosocial skills with offenders without mental
illness (McGuire 1995; Welsh et al. 2002). Preliminary
trials of such programs with offenders who have schizophrenia are currently underway. Furthermore, men with
schizophrenia and APD require community placements in
neighborhoods that support prosocial behaviors and limit
access to offenders, weapons, and drugs (Silver 2000). In
this study, we found that by the time the men with comor-
798
Comorbid Antisocial Personality Disorder
Schizophrenia Bulletin, Vol. 30, No. 4, 2004
bid APD were first admitted to the general psychiatric service, they had a long history of antisocial behavior, substance abuse, poor academic failure, and an adverse family environment, and many already had a criminal record.
There was, therefore, ample evidence for general psychiatric services to identify needs for specific treatments and
services in addition to those traditionally provided to first
onset cases of schizophrenia. Ideally, such patients require
thorough assessments once the psychotic symptoms are
reduced, to identify comorbid APD. Such patients are
likely to require complex treatment plans adapted to their
antisocial personality and placement in neighborhoods
that support and promote positive change. Currently, general psychiatric services in most Western nations do not
have adequate resources and time to provide such assessments and services. Yet the human and financial costs of
not providing such services are high.
The study has a number of strengths. To the best of
our knowledge, it is the first multicenter investigation of
comorbid APD in schizophrenia. Previous studies have
relied on samples of patients drawn from single centers,
thereby reducing the generalizability of their findings.
Well-trained, experienced clinical raters made the assessments, using standardized measures, and information on
childhood was obtained from multiple sources.
Nevertheless, the study has some weaknesses. The sample
was weighted for criminal offending, but, based on the
results of previous studies, not for APD. Given that the
aim of the study was to identify correlates of comorbid
APD among men with schizophrenia, the associations in
our view are generalizable. The findings from the present
study do, however, need to be replicated, preferably in a
sample more representative of the population of persons
with schizophrenia. Despite the expertise of the research
psychiatrists, it proved very difficult to retrospectively
identify the age of onset of the prodrome and of psychosis.
By contrast, the retrospective diagnosis of conduct disorder was less difficult to make, because multiple sources of
information were used to identify externalizing problems
in childhood. Although we tried to reduce type I statistical
error in the univariate analyses by using the Bonferroni
correction, such "playing with p values" may be undesirable. It implies that all outcomes have equal priority and
therefore reduces the power to detect real differences. We
also acknowledge the limitations of using cross-sectional
data to explore etiologic pathways. These data do, however, identify hypotheses for testing in future studies.
Armstrong, T, and Costello, E.J. Community studies on
adolescent substance use, abuse, or dependence and psychiatric comorbidity. Journal of Consulting and Clinical
Psychology, 70:1224-1239, 2002.
Arseneault, L.; Cannon, M.; Poulton, R.; Murray, R.;
Caspi, A.; and Moffitt, T.E. Cannabis use in adolescence
and risk for adult psychosis: Longitudinal prospective
study. British Medical Journal, 32:1212-1213, 2002.
Asarnow, J.R. Children at risk for schizophrenia:
Converging lines of evidence. Schizophrenia Bulletin,
14(4):613-631, 1988.
Blair, R.J.R. Neurobiological basis of psychopathy.
British Journal of Psychiatry, 182:5-7, 2003.
Buhler, B.; Hambrecht, M.; Loffler, W.; an der Heiden,
W.; and Hafner, H. Precipitation and determination of the
onset and course of schizophrenia by substance abuse: A
retrospective and prospective study of 232 populationbased first illness episodes. Schizophrenia Research,
54(Suppl 3):243-251, 2002.
Cannon, T.D.; Mednick, S.A.; and Parnas, J. Antecedents
of predominantly negative and predominantly positive
symptom schizophrenia in a high-risk population.
Archives of General Psychiatry, 47:622-632, 1990.
Caspi, A.; McClay, J.; Moffitt, T.E.; Mill, J.; Martin, J.;
Craig, I.W.; Taylor, A.; and Poulton, R. Role of genotype
in the cycle of violence in maltreated children. Science,
297(5582):851-853, 2002.
Cooke, D.J., and Michie, C. An item response theory
evaluation of Hare's Psychopathy Checklist.
Psychological Assessment, 9:2-13, 1997.
Cooke, D.J., and Michie, C. Refining the construct of psychopathy: Toward a hierarchical model. Psychological
Assessment, 13:171-188,2001.
Frick, P.J.; Cornell, A.H.; Bodin, S.D.; Dane, H.E.; Barry,
C.T.; and Loney, B.R. Callous-unemotional traits and
developmental pathways to severe conduct problems.
Developmental Psychology, 39(2):246-260, 2003.
Gandhi, N.; Tyrer, P.; Evans, K.; McGee, A.; Lamont, A.;
and Harrison-Read, P. A randomised controlled trial of
community-oriented and hospital-oriented care for discharged psychiatric patients: Influence of personality disorder on police contracts. Journal of Personality
Disorders, 15:94-102,2001.
Hare, R.D. The Hare Psychopathy Checklist-Revised:
Manual. Toronto, Canada: Multi-Health Systems, 1991.
Heston, L.L. Psychiatric disorders in foster-home reared
children of schizophrenics. British Journal of Psychiatry,
112:819-825, 1966.
References
American Psychiatric Association. DSM-IV: Diagnostic
and Statistical Manual of Mental Disorders. 4th ed.
Washington, DC: APA, 1994.
Hodgins, S. The etiology and development of offending
among persons with major mental disorders. In: Hodgins,
S., ed. Violence Among the Mentally III: Effective
799
Schizophrenia Bulletin, Vol. 30, No. 4, 2004
P. Moran and S. Hodgins
Treatments and Management Strategies. Dordrecht, The
Netherlands: Kluwer Academic, 2000. pp. 89-116.
Hodgins, S. Criminal and antisocial behaviors and schizophrenia: A neglected topic. In: Gattaz, W., and Hafner, H.,
Mathalon, D.H.; Pfefferbaum, A.; Lim, K.O.;
Rosenbloom, M.J.; and Sullivan, E.V. Compounded brain
volume deficits in schizophrenia-alcoholism comorbidity.
Archives of General Psychiatry, 60:245-252, 2003.
eds. 5th Search for the Causes of Schizophrenia.
McGuire, J., ed. What works: Reducing reoffending—
Guidelines from research and practice. Chichester, U.K.:
Wiley, 1995.
Darmstadt, Germany: Steinkopff Verlag, 2004. pp.
315-341.
Hodgins, S., and Cote, G. The criminality of mentally dis-
Moffitt, T.E., and Caspi, A. Childhood predictors differentiate life-course persistent and adolescence-limited antisocial pathways among males and females. Development
and Psychopathology, 13:355-375, 2001.
ordered offenders. Criminal Justice and Behavior,
28:115-129, 1993.
Hodgins, S.; Cote, G.; and Toupin, J. Major mental disorders and crime: An etiologic hypothesis. In: Cooke, D.;
Forth, A.; and Hare, R.D., eds. Psychopathy: Theory,
Research and Implications for Society. Dordrecht, The
Netherlands: Kluwer Academic, 1998. pp. 231-256.
Hodgins, S., and Janson, C-G. Criminality and Violence
Moran, P.; Walsh, E.; Tyrer, P.; Burns, T; Creed, F.; and
Fahy, T. The impact of co-morbid personality disorder on
violence in psychosis—data from the UK700 trial. British
Journal of Psychiatry, 182:129-134, 2003.
Mueser, K.T.; Drake, R.E.; Ackerson, T.H.; Alterman,
A.I.; Miles, K.M.; and Noordsy, D.L. Antisocial personality disorder, conduct disorder, and substance abuse in
Among the Mentally Disordered: The Stockholm
Metropolitan Project. Cambridge, U.K.: Cambridge
University Press, 2002.
schizophrenia. Journal of Abnormal Psychology,
Hodgins, S., and Miiller-Isberner, R., eds. Violence, Crime
and Mentally Disordered Offenders: Concepts and
Methods for Effective Treatment and Prevention.
106:473-477, 1997.
Mueser, K.T.; Rosenberg, S.D.; Drake, R.E.; Miles, K.M.;
Wolford, G.; Vidaver, R.; and Carrieri, K. Conduct disorder, antisocial personality disorder and substance use disorders in schizophrenia and major affective disorders.
Journal of Studies on Alcohol, 60:278-284, 1999.
Chichester, U.K.: John Wiley and Sons, 2000.
Hodgins, S.; Tengstrom, A.; Ostermann, R.; Eaves, D.;
Hart, S.; Konstrand, R.; Levander, S.; Miiller-Isberner, R.;
Tiihonen, J.; Webster, C D . ; Eronen, M.; Freese, R.;
Jockel, D.; Kreuzer, A.; Levin, A.; Maas, S.; Repo, E.;
Ross, D.; Tuninger, E.; Kotilainen, I.; Vaananen, K.;
Vartianen, H.; and Vokkolainen, A. An international comparison of community treatment programs for mentally ill
persons who have committed criminal offences. Criminal
Justice and Behavior, in press.
Parnas, J. Assortative mating in schizophrenia: Results
from the Copenhagen High-Risk Study. Psychiatry,
51:58-64,1988.
Rhee, S.H., and Waldman, I.D. Genetic and environmental influences on antisocial behavior: A meta-analysis of
twin and adoption studies. Psychological
Bulletin,
128:490-529,2002.
Hodgins, S.; Toupin, J.; and Cote, G. Schizophrenia and
antisocial personality disorder: A criminal combination.
In: Schlesinger, L.B., ed. Explorations in Criminal
Psychopathology: Clinical Syndromes with Forensic
Implications. Springfield, IL: Charles C. Thomas, 1996.
pp. 217-237.
Robins, L.N. Childhood conduct problems, adult psychopathology, and crime. In: Hodgins, S., ed. Mental
Disorder and Crime. Newbury Park, CA: Sage
Publications, 1993. pp. 173-207.
Robins, L.N., and McEvoy, L. Conduct problems as predictors of substance abuse. In: Robins, L.N., and Rutter,
M., eds. Straight and Deviant Pathways From Childhood
to Adulthood. Cambridge, U.K.: Cambridge University
Press, 1990. pp. 182-204.
Hunt, G.E.; Bergen, J.; and Bashir, M. Medication compliance and comorbid substance abuse in schizophrenia:
Impact on community survival 4 years after a relapse.
Schizophrenia Research, 54(Suppl 3):253-264, 2002.
Kay, S.R. Significance of the positive-negative distinction in
schizophrenia. Schizophrenia Bulletin, 16(4):635-652, 1990.
Kay, S.R.; Fiszbein, A.; and Opler, L.A. The Positive and
Negative Syndrome Scale (PANSS) for schizophrenia.
Schizophrenia Bulletin, 13(2):261-276, 1987.
Robins, L.N., and Price, R.K. Adult disorders predicted
by childhood conduct problems: Results from the NIMH
Epidemiologic Catchment Area project. Psychiatry,
54:116-132, 1991.
Robins, L.N.; Tipp, J.; and Przybeck, T. Antisocial personality. In: Robins, L.N., and Regier, D., eds. Psychiatric
Disorders in America: The Epidemiologic Catchment
Area Study. New York, NY: Mac mi 11 an/Free Press, 1991.
pp. 258-290.
Kim-Cohen, J.; Caspi, A.; Moffitt, T.E.; Harrington, H.;
Milne, B.J.; and Poulton, R. Prior juvenile diagnoses in
adults with mental disorder. Archives of General
Psychiatry, 60:709-714, 2003.
800
Comorbid Antisocial Personality Disorder
Schizophrenia Bulletin, Vol. 30, No. 4, 2004
Sheilagh Hodgins, Ph.D., Institute of Psychiatry, King's
College, London; Derek Eaves, M.D., Vancouver, Canada;
Markku Eronen, M.D., Ph.D., Vanha Vaasa Hospital,
Vaasa, and Niuvanniemi Hospital, Kuopio, Finland;
Stephen Hart, Ph.D., Simon Fraser University, Burnaby,
Canada; Robert Kronstrand, Ph.D., Rattsmedicinalverket
and Linkoping University, Linkoping, Sweden; Sten
Levander, M.D., Ph.D., University Hospital, MAS,
Malmo, Sweden; Riidiger Miiller-Isberner, Dr.med., Klinik
filr forensische Psychiatrie Haina, Haina (Kloster),
Germany; Jari Tiihonen, M.D., Ph.D., University of
Kuopio, Finland; Christopher Webster, Ph.D., Simon
Fraser University, Burnaby, Canada, and McMaster
University, Hamilton, Canada; Roland Freese, M.D.,
Klinik fiir forensische Psychiatrie Haina, Haina (Kloster),
Germany; Andrea Grabovac, M.D., Riverview Hospital,
Vancouver, Canada; Dieter Jockel, D.med., Klinik fiir
forensische Psychiatrie Haina, Haina (Kloster), Germany;
Artur Kreuzer, Dr.jur., Justus Liebig University, Giessen,
Germany; Alexander Levin, M.D., Vancouver General
Hospital, Vancouver, Canada; Stephanie Maas, Klinik fiir
forensische Psychiatrie Haina, Haina (Kloster), Germany;
Eila Repo-Tiihonen, M.D., Ph.D., Niuvanniemi Hospital,
Kuopio, Finland; Deborah Ross, M . S c , Riverview
Hospital, Coquitlam, Canada; Eva Tuninger, M.D.,
University Hospital, MAS, Malmo, Sweden; Irma
Kotilainen, M.D., University of Kuopio, Kuopio, Finland;
Kirsi Vaananen, Niuvanniemi Hospital, Kuopio, Finland;
Paivi Toivonen, M.D., Vanha Vaasa Hospital, Vaasa,
Finland; Heikki Vartiainen, M.D., Ph.D., Helsinki Central
University Hospital, Helsinki, Finland; Aila Vokkolainen,
Vanha Vaasa Hospital, Vaasa, Finland; Jean-Francois
Allaire, M.Sc, Institut Philippe Pinel de Montreal,
Montreal, Canada; and Anders Tengstrom, Ph.D., MariaUngdom Research Centre, Karolinska Institute,
Stockholm, Sweden.
Grants to support this study have been awarded
by the following sources:
1. The European Union's BIO-MED-II program.
Scott, S.; Spender, Q.; Doolan, M.; Jacobs, B.; Aspland,
H.; and Webster-Stratton, C. Multicentre controlled trial
of parenting groups for childhood antisocial behaviour in
clinical practice. British Medical Journal, 323:194-198,
2001.
Silver, E. Race, neighbourhood, disadvantage, and violence among persons with mental disorders: The importance of contextual measurement. Law and Human
Behavior, 24(Suppl 4):449^56, 2000.
Silverton, L. Crime and the Schizophrenia Spectrum: A
Study of Two Danish Cohorts. Unpublished doctoral dissertation, University of Southern California, 1985.
Spitzer, R.L.; Williams, J.B.W.; Gibbon, M.; and First,
M.B. The Structured Clinical Interview for DSM-III-R
(SCID) I: History, rationale, and description. Archives of
General Psychiatry, 49:624-629, 1992.
Stata Corporation. Stata Statistical Software. Release 7.0.
College Station, TX: Stata Corporation, 2001.
Tengstrom, A., and Hodgins, S. Assessing psychopathic
traits among persons with schizophrenia: A way to
improve violence risk assessment. In: Blaauw, E., and
Sheridan, L., eds. Psychopaths: Current International
Perspective. The Hague, The Netherlands: Elsevier, 2002.
pp. 81-111.
Tengstrom, A.; Hodgins, S.; and Kullgren, G. Men with
schizophrenia who behave violently: The usefulness of an
early- versus late-start offender typology. Schizophrenia
Bulletin, 27(2):205-218, 2001.
Torgalsb0en, A-K. Co-morbidity in schizophrenia: A
prognostic study of personality disorders in recovered and
non-recovered schizophrenia patients. Scandinavian
Journal of Psychology, 40:147-152, 1999.
Tyrer, P., and Simmonds, S. Treatment models for those
with severe mental illness and comorbid personality disorder. British Journal of Psychiatry, 182(Suppl): 15—18,
2003.
Welsh, B.C.; Farrington, D.P.; Sherman, L.W.; and
MacKenzie, D.L. What do we know about crime prevention. International Annals of Criminology, 40(1/2): 11-31,
2002.
Zammit, S.; Allebeck, P.; Andreasson, S.; Lundberg, I.;
and Lewis, G. Self-reported cannabis use as a risk factor
for schizophrenia in Swedish conscripts of 1969:
Historical cohort study. British Medical
Journal,
325:1199-1201,2002.
2.
Funding in Canada came from the Forensic
Psychiatric Services Commission of British
Columbia; the Mental Health, Law, and Policy
Institute, Simon Fraser University; Riverview
Hospital.
3.
Funding in Finland came from Niuvanniemi and
Vanha Vaasa State Mental Hospitals.
4.
Funding in Germany came from Deutsche
Forschungsgemeinschaft, Institut fiir forensische
Psychiatrie Haina.
5.
Funding in Sweden came from Medicinska
Forskningradet, Vardalstiftelsen; National Board of
Acknowledgments
The Comparative Study of the Prevention of Crime and
Violence by Mentally 111 Persons is being conducted by
801
Schizophrenia Bulletin, Vol. 30, No. 4, 2004
P. Moran and S. Hodgins
Forensic Medicine; Forensic Science Centre,
Linkoping University; and Linkoping University.
The Authors
Paul Moran is funded by a postdoctoral fellowship
awarded by the National Health Service National
Programme on Forensic Mental Health. The views expressed
in this article are those of the authors and not necessarily
those of the Programme or the U.K. Department of Health.
802
Paul Moran, M.D., MRCPsych, is Postdoctoral Research
Fellow and Honorary Consultant Psychiatrist, Health
Services Research Department, Institute of Psychiatry,
London, U.K. Sheilagh Hodgins, M.Sc, Ph.D., is Head,
Department of Forensic Mental Health Science, Institute
of Psychiatry, London, U.K.