Advances in psychiatric treatment (2010), vol. 16, 37–43 doi: 10.1192/apt.bp.107.005082 Asperger syndrome and criminal ARTICLE behaviour† Kalpana Dein & Marc Woodbury-Smith has been concerned with the basic sciences rather Kalpana Dein is a consultant SUMMARY than everyday clinical issues (summarised in Klin forensic psychiatrist working in Clare House (St Andrew’s The importance of considering antisocial behaviour 2005). More specifically, very little has focused on among people with autism-spectrum disorders is Healthcare, Essex, UK). She has people with autism who come into contact with the a special interest in offenders apparent from the significant number of case reports criminal justice system. with autistic disorders. She and case series describing criminal behaviour of Offending and antisocial behaviour in the context is pursuing an MD in Clinical people with a diagnosis of Asperger syndrome. Research at University College The evidence so far does not support a specific of Asperger syndrome have been described in a London, exploring high-functioning association between the syndrome and criminal number of case reports and case series (Woodbury- autism in mentally disordered offending. However, a small yet significant number Smith 2005; Mouridsen 2008). Asperger himself, in offenders. Marc Woodbury- Smith is Assistant Professor in of offenders with autism who engage in illegal his original paper, described antisocial behaviour the Department of Psychiatry behaviour find themselves socially excluded or in addition to the core clinical impairments (Frith and Behavioural Neurosciences, detained in secure provisions for prolonged periods. 1991). Wing (1981: p. 116) similarly made reference McMaster University, Canada. He This article gives an overview of the scant empirical to a small minority with a history of ‘bizarre anti- trained in psychiatry in Southampton and Cambridge in the UK, and evidence relating to criminality within the context social acts’ in her case series of 34 children and of Asperger syndrome, and offers suggestions for at Yale University in the USA. adults with Asperger syndrome. managing the syndrome in mentally disordered During his time in Cambridge he completed his PhD thesis offenders. Prevalence in forensic populations ‘Exploring criminal behaviour among DeclaratiON OF INTEREST people with Asperger’s disorder’. A study in Broadmoor Hospital, one of England’s Correspondence None. Marc Woodbury-Smith, McMaster three high-security psychiatric hospitals, estimated University, Department of Psychiatry that 1.5–2.3% of the hospital’s male population had and Behavioural Neurosciences, Autism-spectrum disorders are a group of biologi- Asperger syndrome or autism-spectrum disorder Chedoke Site, Evel Building (Room cally based behavioural syndromes of childhood (if equivocal cases were included) (Scragg 1994). 457), Hamilton, ON Canada L8N 3Z5. Email: [email protected] onset that are characterised by qualitative impair- This significantly exceeds the 0.36% prevalence ments in reciprocal social interaction and verbal estimated for the general population using the † and non-verbal communication, together with same criteria (Allen 2007). This overrepresentation For a commentary on this article, see pp. 44–46, this issue. a restricted and repetitive range of behaviours, of Asperger syndrome (at least 1.68%, n = 22) interests and activities – the so-called ‘triad of was subsequently confirmed in all three English impairments’ (Wing 1981). Among individuals high secure units (Hare 1999). In a sample of 72 with ‘high-functioning autism’, the term ‘Asperger men referred to the dangerous severe personality syndrome’ is reserved for people for whom the social disorder unit of Her Majesty’s Prison Whitemoor, interaction and restricted patterns of behaviour two prisoners were given a definite diagnosis of occur in the context of normal early language Asperger syndrome and four a provisional diagnosis and cog nitive development. Although people with (in the absence of parental accounts), suggesting a Asperger syndrome do not have the communication prevalence of 2.7–8.3%. A further four men showed impairments typical of autistic disorder, a number autistic traits (Hawes 2003). Interestingly, much of specific pragmatic abnormalities are recognised lower prevalences, of 0.46% in secure psychiatric (for further discussion see Klin 2005). units and 0.93% in the prison service, have been The syndrome itself was first described by the reported in Scotland (Myers 2004). Viennese paediatrician Hans Asperger in 1944. In contrast to these UK estimates, in a group Diagnostic features of the syndrome, however, were of Swedish young offenders referred for forensic not operationalised until ICD–10 (World Health assess ments in Stockholm, 15% were diagnosed Organization 1992) and DSM–IV (American with a definite autism-spectrum disorder and a Psychiatric Association 1994). further 12% with a probable disorder of this type The scientific literature concerned with autism- (Siponmaa 2001). spectrum disorders has increased enormously All of these findings are surprising, given that over the past two decades, although much of it a Danish study found that the rate of conviction 37 Dein & Woodbury-Smith of people with Asperger syndrome was similar this result was not statistically significant) to that for people without (P = 0.89), and that the (Woodbury-Smith 2006), and there is evidence conviction rate of people with atypical autism that offenders with autism-spectrum disorders was lower than that of people without (P = 0.14) are more likely to have previous convictions for (Mouridsen 2008). Similarly, a low rate of law- assault (Elvish 2007). Similar rates of violent breaking behaviour (using both self-report and offending by patients with autism-spectrum official data) was found in a UK community sample disorders have been reported in high secure units of people with Asperger syndrome (Woodbury- in England (Hare 1999). However, a subsequent Smith 2006). study in Broadmoor Hospital found that patients Thus, the literature is difficult to interpret, but with Asperger syndrome had comparatively lower it seems reasonable to conclude that, even though violence ratings for their index offence than did the prevalence of the syndrome is higher than other patients (Murphy 2003). expected in forensic psychiatric populations, this does not reflect a raised rate of convictions, or Characteristics of offenders indeed a raised rate of offending, in the community. A number of factors may mediate offending in Nevertheless, it is important for clinicians to be people with Asperger syndrome (Box 1) and some aware of autism-spectrum disorders in offenders. of these are considered below. An early diagnosis and intervention may reduce the risk of future offending. Gender The nature of the offences committed As would be expected, the majority of offenders are men, although little is known about their socio- A wide variety of offences are represented in the economic status or ethnicity. Factors associated literature. There is growing evidence that people with the risk of offending in the general population, with Asperger syndrome are more likely to commit such as poor educational achievement, truancy, fire-setting offences than people without the aggressive behaviour, hyperactivity/impulsivity syndrome (Hare 1999; Siponmaa 2001; Mouridsen and inattention (Woodbury-Smith 2006), may all 2008). Both alcohol and drug misuse (Schwartz- be relevant in Asperger syndrome as well. Social Watts 2005) and drug offences (Allen 2007) exclusion is not an unusual experience for people have been reported in this population, although with autism-spectrum disorders, and for a small substance use is comparatively rare (Murphy minority feelings of powerlessness and resentment 2003; Woodbury-Smith 2006; Mouridsen 2008). resulting from marginalisation may lead to Epidemiological studies indicate that people with malicious acts (Woodbury-Smith 2006). Asperger syndrome do commit sexual offences A number of studies (e.g. Hare 1999; Mouridsen (Hare 1999; Murphy 2003), but there is evidence 2008) indicate that women with autism-spectrum that the rates of sexual offending in general (Hare disorders are more prone to antisocial behaviour 1999), and of child sex offences in particular than are other women. Crocombe et al (2006) found (Elvish 2007), are lower among offenders with that 6 out of 51 women (over 10%) in a high secure autism-spectrum disorders. unit met ICD–10 criteria for an autism-spectrum As regards violent offences, (self-)reported disorder. The characteristics of female offenders violence in a community sample was more common with Asperger syndrome and the reasons for their among those with Asperger syndrome (although apparent overrepresentation within criminal populations warrant further investigation. BOX 1 Factors that may mediate offending in Asperger syndrome Comorbidity • General factors: • Comorbid psychiatric conditions: One of the few studies to have examined comorbidity poor educational achievement conduct disorder among offenders with autism-spectrum disorders truancy antisocial personality disorder reported that none of its sample of male patients aggressive behaviour schizophrenia with Asperger syndrome in a high secure hospital hyperactivity/impulsivity affective disorders (e.g. bipolar affective had any history of serious antisocial behaviour or inattention disorder, depression) criminal convictions before the age of 18 (Murphy 2003). In contrast,