Schizophrenia

O R I G I N A L P A P E R

Violent Crime in Asperger Syndrome: The Role of Psychiatric Comorbidity

Stewart S. Newman Æ Mohammad Ghaziuddin

Published online: 1 May 2008

� Springer Science+Business Media, LLC 2008

Abstract Although several studies have suggested an

association between violent crime and Asperger syndrome

(AS), few have examined the underlying reasons. The aim

of this review is to determine to what extent psychiatric

factors contribute to offending behavior in this population.

Online databases were used to identify relevant articles

which were then cross-referenced with keyword searches

for ‘‘violence,’’ ‘‘crime,’’ ‘‘murder,’’ ‘‘assault,’’ ‘‘rape,’’ and

‘‘sex offenses.’’ Most of the 17 publications which met the

inclusion criteria were single case reports. Of the 37 cases

described in these publications, 11 cases (29.7%) cases had

a definite psychiatric disorder and 20 cases (54%) had a

probable psychiatric disorder at the time of committing the

crime. These findings underscore the role of psychiatric

disorders in the occurrence of violent crime in persons with

Asperger syndrome and highlight the need for their early

diagnosis and treatment.

Keywords Crime � Violence � Asperger syndrome � Autism � Comorbidity

Introduction

Asperger syndrome (AS) was first described under the title

‘‘autistic psychopathy’’ by Hans Asperger, an Austrian

physician interested in the habilitation of children with

behavioral problems (Asperger 1944). Fifty years after its

initial description, it was introduced as a distinct category

in the DSM-IV (APA 1994) and the ICD-10 (WHO 1993).

At present, it is conceptualized as a variant of autism,

marked by social deficits and intense focused interests in

the presence of normal intelligence and relatively well-

preserved communication skills. In addition, most affected

persons have an odd and pedantic manner of speaking

(Klin et al. 2005); and poor nonverbal communication

(Wing 1981). Although its exact prevalence is uncertain, it

is being increasingly recognized in children and adults.

Recent figures place its prevalence rate between one and

five per thousand (Chakrabarti and Fombonne 2005;

Mattila et al. 2007).

An interesting but controversial aspect of Asperger syn-

drome is its association with violent crime. Although

Asperger used the label ‘‘autistic psychopathy’’ as a stable

personality style and not as an index of criminality, reports

have continued to describe links between AS and violent

crime. It was probably Mawson et al. (1985) who first

reported an association between Asperger syndrome and

violent crime. They described a 44-year-old man who had a

long history of violent behavior that led to frequent admis-

sions to psychiatric hospitals (Mawson et al. 1985). A few

years later, Baron-Cohen (1988) described a 21-year-old

man with a history of recurrent violence towards his 71-year-

old girlfriend. The author speculated that while the primary

cause of the patient’s violent feelings could not be ascer-

tained, one factor that maintained them was his deficit in

social cognition (Baron-Cohen 1988). Ghaziuddin et al.

S. S. Newman

University of Oregon, Eugene, OR, USA

Present Address: S. S. Newman

Private Practice, Portland, OR, USA

M. Ghaziuddin (&) University of Michigan, Ann Arbor, MI, USA

e-mail: [email protected]

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J Autism Dev Disord (2008) 38:1848–1852

DOI 10.1007/s10803-008-0580-8

(1991) reviewed the published literature on this topic from

1994 to 1990 and concluded that there was no clear associ-

ation between AS and violent crime and suggested that

people with AS were no more likely to commit violent crime

than the rest of the population (Ghaziuddin et al. 1991).

However, since the publication of that review, reports

have continued to appear suggesting a link between As-

perger syndrome and crime, especially violent crime,

including murder (Schwartz-Watts 2005). Several mecha-

nisms have been suggested to explain this association, such

as, lack of empathy; social naiveté, excessive interests

getting out of control etc. Some authors have focused on

the tendency of persons with AS to collect objects of

special interest as a prelude to criminal behavior. Thus,

Chen et al. (2003) described a 21-year-old male with As-

perger syndrome who had a history of repeatedly stealing

certain objects, such as, plastic bags, boxes and paper cups

(Chen et al. 2003). Others have suggested that persons with

AS sometimes indulge in criminal behavior because of

their sexual preoccupations. For instance, Chesterman and

Rutter (1993) described a 22-year-old male with Asperger

syndrome who had a history of stealing cotton lingerie and

masturbating while holding women’s nightdresses. Kohn

et al. (1998) described a 16-year-old male with Asperger

syndrome who had the habit of grabbing and fondling

women in an attempt to make them his ‘girlfriends.’ Milton

et al. (2002) described the case of a Caucasian male in his

early thirties with AS who had a history of recurrent sexual

offences, such as, touching the private parts of young

women; watching women in public toilets; and making

obscene phone calls at times pretending to be a gynecol-

ogist. Bankier et al. (1999) discussed the case of a 25-year-

old male with a history of selective mutism, severe social

withdrawal, and recurrent violence against his mother, who

met the profile of Asperger syndrome. In addition, at least

two reports have suggested that persons with AS may be

predisposed to committing arson. Everall and LeCouteur

(1990) described a 17-year-old boy with a history of fire-

setting. In a retrospective study examining the role of

neuropsychiatric disorders in a group of 126 juvenile

offenders referred to a forensic service in Sweden, Sip-

onmaa et al. (2001) found four persons with definite

Asperger syndrome. The diagnoses of Asperger syndrome

and PDDNOS were over-represented in the arson group

than it was in any other offending group (Siponmaa et al.,

2001).

Few studies, however, have examined the role of psy-

chiatric factors that might contribute to the occurrence of

violent crime in this population. In one of the few reports

on this topic, Palermo (2004) emphasized the importance

of psychiatric factors by describing two cases of AS and

one of PDDNOS, all of whom had a history of violence and

arson, and additional psychiatric disorders. Other reports

have alluded to the psychiatric status of the offenders but

not provided enough details. Surveys of special hospitals,

for example, have found an excess of persons with AS.

Scragg and Shah (1994) studied the entire male population

in a maximum security hospital in the U.K., and found nine

subjects who met the characteristics of Asperger syndrome.

The authors concluded that the rate of AS was higher in

that hospital than that in the general population. There have

also been reports in the media, especially in the United

States, speculating on an association between AS and

random acts of campus violence in the United States. Thus,

despite the public health importance of the topic, relatively

little is known about the psychiatric status of violent

offenders with Asperger syndrome. The purpose of this

review is to examine this issue.

Method

We performed an extensive computer-assisted search of

professional databases including MEDLINE, CINAHL,

Cochrane database of systematic reviews, and pertinent

textbooks and related resources, to identify all published

papers describing the association of Asperger syndrome

with crime and violence. Reference lists of articles were

also examined for additional sources. Searches were per-

formed using the keywords ‘Asperger syndrome,’

‘pervasive developmental disorders;’ and ‘autistic psy-

chopathy.’ These categories were cross referenced with the

keywords ‘‘violence,’’ ‘‘crime,’’ ‘‘murder,’’ ‘‘assault,’’

‘‘rape,’’ and ‘‘sex offenses.’’ The articles were reviewed to

determine if they included sufficient information of the

criminal behavior.

For the purpose of this review, violent crime was defined

as any act for which the person could be charged with a crime

(including but not limited to murder, attempted murder,

assault and/or battery, sexual assault, arson, stalking, rob-

bery) or which resulted in a significant injury to another

person. Since the study was based on the information already

contained in the published reports, it was not possible to

examine the motives or the reasons for the violent act.

Therefore, the definition of violent crime was based on the

observed behavior and its consequences rather than the

intent. Temper tantrums, nonspecific behavioral problems,

and self-injurious behaviors were excluded. Articles were

also excluded if they did not include sufficient information to

determine the diagnosis of the subjects or a detailed

description of the criminal behavior. Only articles published

in English were reviewed.

Subjects were divided into three categories; those with

definite psychiatric disorder; those with probable psychi-

atric disorder; and those with no clear evidence of a

psychiatric disorder. To be classified as suffering from a

J Autism Dev Disord (2008) 38:1848–1852 1849

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‘‘definite’’ psychiatric disorder, the subject had to have a

psychiatric diagnosis given by a psychiatrist and/or to have

symptoms and behavior described in sufficient detail to

allow for a diagnosis to be made. Cases that probably had a

psychiatric illness but did not have enough details descri-

bed of their behavior were classified as having had a

‘‘probable’’ psychiatric disorder. Finally, cases who had no

evidence of a psychiatric disorder based on the description

given in the report were classified as not having any such

disorder. The first author examined the case histories and

then both the authors, after discussion, jointly categorized

whether or not the act described in the publication met the

inclusion criteria.

Results

Computerized database searches yielded 59 candidate

articles for review. An additional 13 articles were found

through reference lists, resulting in a total of 72 publica-

tions. Of these, 54 were excluded for not meeting the

inclusion criteria, leading to a total of 18 publications.

Another article (Anckarsater 2005) was excluded because,

on further examination, it had the same cases that had been

included in a previous publication (Soderstrom et al.

2005). This led to a total of 17 publications and 37 cases.

Of these, 11 (29.7%) cases had evidence of a definite

psychiatric disorder and 20 (54%) cases of probable psy-

chiatric disorder. In only six cases (16.2%), was there no

clear evidence of a comorbid psychiatric disorder

(Table 1).

Discussion

The main finding of the study is that an overwhelming

number of cases had co-existing psychiatric disorders at the

time of committing the offence. Eleven cases (29.7%)

cases had a definite psychiatric disorder and 20 cases

(54%) had a probable psychiatric disorder. Examples of

cases with a definite psychiatric disorder included the three

cases described by Palermo (2004) had comorbid psychi-

atric disorders (ADHD and Mood Disorders). Four of the

34 cases in Wing’s study were categorized as having a

definite psychiatric disorder (Wing 1981). In Baron-

Cohen’s (1988) study, the patient, a 21-year-old man,

believed that he looked like a werewolf and was obsessed

with his jaw. He too was classified as having a definite

psychiatric disorder. All the nine cases described by Scragg

and Shah (1994) were in a maximum security hospital for

mentally ill offenders. Because sufficient details of their

behavior were not given, these nine cases were classified as

having a probable psychiatric disorder. Thus, on the whole,

the findings suggest that impairment of mental health may

be an important reason why some persons with Asperger

syndrome commit violent criminal acts.

The association between violent crime and mental

health is well established (Swanson et al. 1990). Psychi-

atric problems are over-represented among violent

offenders although the nature of the association between

psychiatric disorder and criminality is not clearly under-

stood. Factors such as substance abuse; family history of

criminality and other psychosocial stressors are also

important. Therefore, when violent crime occurs in the

Table 1 Psychiatric comorbidity of AS subjects with violent criminal behavior

Study N Psychiatric disorder Comments

Wing (1981) 4 Definite ‘‘Bizarre and antisocial acts’’

Mawson et al. (1985) 1 Probable History of psychiatric admissions

Baron-Cohen (1988) 1 Definite Obsessed with his jaw. Probable dysmorphophobia

Everall and Lecouteur (1990) 1 Not clear No clear comorbid diagnosis. Compulsive fire-setter

Chesterman and Rutter (1993) 1 Probable Probable Obsessive Comp Disorder. ‘‘Personality Disorder’’

Scragg and Shah (1994) 9 Probable All patients probably had a comorbid psychiatric diagnosis

Kohn et al. (1998) 1 Probable Diagnosed with ‘conduct disorder

Bankier et al. (1999) 1 Probable Diagnosed with ‘‘obsessional neurosis’’

Siponmaa et al. (2001) 4 Probable History of fire-setting

Milton et al. (2002) 1 Nil No comorbid diagnosis. Paraphilia and serial sexual offenses

Silva et al. (2002) 1 Nil Case report on Jeffery Dahmer. Diagnosis doubtful

Silva et al. (2003) 1 Not clear Case report on Theodore Kaczynski, History not clear

Palermo (2004) 3 Definite Pt 1: ADHD; Pt 2: Depression; Pt 3: Mood disorder

Silva et al. (2005) 1 Nil Case report on Joel Rifkin, Diagnosis doubtful

Schwartz-Watts (2005) 3 Cases 1 & 3, Definite Pt 1: Overdose, 3: Nil; 3: Schizoaffective disorder

Soderstrom et al. (2005) 3 Probable From 100 admissions to forensic hospital

Haskins and Silva (2005) 1 Definite Major Depression

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setting of Asperger syndrome, the cause may lie as much in

the diagnosis of AS as in the other factors that contribute to

its occurrence in the general population, including

comorbid mental disorders.

Persons with Asperger syndrome have sometimes been

described as lacking in empathy and in their ability to

experience the feelings and emotion states of others. In

fact, diagnostic measures of autism often incorporate

questions dealing with the child’s ability to share feelings

with and offer comfort to others. As an extension of this

belief, persons with Asperger syndrome have been descri-

bed as lacking in conscience, which increases their risk for

committing crime. However, although some persons with

Asperger syndrome may be described as defiant and

oppositional, aggressive behavior is not one of its defining

or discriminating features (DSM, APA 1994).

It is important to emphasize that six cases (15%) did not

have any comorbid psychiatric disorder which suggests that

some persons with AS indulge in violent crime for no

apparent reason. These persons may meet the criteria for

antisocial personality disorder although the two conditions

are regarded as distinct entities (Wing 1981). In a cohort of

violent offenders, Anckarsater (2005) found that 18 of the

89 offenders subjects had a history of an ASD (five cases

had autism; three had Asperger syndrome and 10 had

atypical autism). Although Asperger sydnrome symptoms/

autistic traits were positively correlated with the Psy-

chopathy Checklist-Revised scores (PCL-R; Hare 1991),

the superficiality that characterized psychopathy was dif-

ferent from the social disability of autism (Anckarsater

2005). Studies comparing differences in the social

impairment of AS with those of conduct disorder (which is

often regarded as a forerunner of antisocial personality

disorder) have also reached similar conclusions (Green

et al. 2000).

Since the study consisted of 37 subjects, it may be

criticized as being too restrictive and hence not being

representative. The most common reason why subjects

were excluded was a lack of clarity about the diagnosis.

For instance, two reports were excluded because the sub-

jects had mental retardation (Simblett and Wilson 1993;

Cooper et al. 1993), which is not consistent with a diag-

nosis of Asperger syndrome based on the DSM-IV (APA

1994) criteria. In other cases, the diagnosis was made for

the first time in adulthood without a reliable early devel-

opmental history (for example, Murrie et al. 2002).

Another reason why subjects were excluded was a lack of

clarity about the reason for referral and insufficient

description of the offending behavior. Thus, the study by

Mandell and colleagues (2005) was excluded because the

nature of the behavioral problems was not specified.

Another study was excluded because the offender had a

history of stealing (Chen et al. 2003) but not of any violent

crime. Finally, one study (Anckasarter 2005) was excluded

because its sample was common to another study that was

included (Soderstrom et al. 2005). Thus, on the whole, the

findings of our study seem to be representative of persons

with Asperger syndrome referred to specialist services.

Our review did not attempt to find out if, based on recent

literature, persons with AS can be described as being at

greater risk of committing violent crime than the general

population. For this purpose, systematic population-based

studies are required. In perhaps the only study of its kind,

Woodbury-Smith and colleagues (2006) compared the rates

of offending behavior in a community sample of persons

with high-functioning forms of ASD with a matched gen-

eral population control group. Although the study was

based on a small sample of 24 cases, and did not examine

the psychiatric comorbidity of the offenders in a systematic

manner, its findings provide further support that persons

with ASD do not seem to be at an increased risk of criminal

behavior. More studies of this nature are urgently needed.

In conclusion, this review found that most of the cases

of Asperger syndrome who commit violent crime suffer

from additional psychiatric disorders. While this finding in

itself does not fully explain why some persons with AS

commit violent crimes, it suggests that co-existing mental

disorders raise the risk of offending behavior in this group,

as it does in the general population. Thus, persons with AS

charged with violent crimes should be examined for the

presence of additional psychiatric disorders. Clinicians

should look beyond the diagnosis of AS and attempt to

explore the factors that might contribute to criminal

behavior in this population. In addition, professionals

working in forensic settings should be trained in the rec-

ognition and treatment of persons with autistic spectrum

disorders and special services should be designed for

mentally ill offenders with Asperger syndrome.

Acknowledgments The authors acknowledge their gratitude to Cheryl King, Ph.D. and to the NARSAD Foundation.

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