Author
BJORKLY Stal;
Risk and dynamics of violence in Asperger's syndrome: a systematic review of the literature.
Journal citation/publication details
Aggression and Violent Behavior, 14(5), September/October 2009, pp306-312.
Summary
Only eleven studies on the association of violent behaviour and Asperger's syndrome (AS) were identified; the majority were case studies. The limited findings, based on 29 violent incidents, are described in terms of motives, triggers, types, and victims of violence but the evidence did not support the link between AS and violence. The bulk of the paper involves a discussion of the qualitative findings in relation to diagnostic issues, empathy deficiency, impairment in social interaction, and the risk for violence compared to psychopathy. Suggestions for future research are outlined.
Context
Previous research has indicated that there may be a link between AS and violence but the prevalence estimates are highly divergent and the evidence is limited by a lack of valid and reliable diagnostic instruments for AS. The aims of this review were '(a) to examine the empirical basis for the existence of a relationship between Asperger's syndrome and violence risk (b) to determine whether certain characteristics of Asperger's syndrome may have a higher violence-triggering potential, and (c) to compare possible characteristics of violence in persons with Asperger's syndrome with those found in persons with psychopathy'.
Methods
What sources were searched?
The following electronic sources were searched up to mid February 2007: CINAHL (from 1982), Cochrane Reviews (from 1992), Medline (from 1966), ProQuest (from 1992), PsycINFO (from 1967), and ScienceDirect (from 1995). Additional studies were identified by hand searching the reference lists of relevant papers.
What search terms/strategies were used?
The search terms used were 'Asperger's syndrome and risk assessment or risk management and violence risk or violence or violent behaviour or aggression or aggressive behaviour and psychiatric patients or psychotic patients or psychosis or forensic patients or personality disorders'. Two searches were carried out the first with the additional term 'review of' and the second without. Further details of the search strategy are not included.
What criteria were used to decide on which studies to include?
Studies were eligible for inclusion if they included qualitative or quantitative data on AS and violence and patients met the ICD-10 criteria for AS and DSM-IV criteria for Asperger's disorder. Violence was defined as that aimed toward another individual according to the criteria used in the MacArthur Violence Risk Assessment Study. Only studies published as full papers in the English language in peer reviewed journals were included.
Who decided on their relevance and quality?
Articles were assessed against the inclusion criteria in three stages: by title, abstract and full text. There is no indication that the quality of the included studies was formally assessed.
How many studies were included and where were they from?
The total number of references initially retrieved was 147. The number of studies rejected at each stage is detailed in Fig.1. Seven studies identified from the electronic search and four papers from the hand searches were included in this review. Five of the studies were set in England, two in Israel and one each in Austria, USA, Australia/New Zealand, and Italy.
How were the study findings combined?
The results are presented as a narrative synthesis.
Findings of the review
Five of the 11 studies included an investigation into the link between AS and violence in the research aims. Three of the eleven studies were prevalence studies the other eight were case studies describing a total of 14 patients with AS and violence (all male aged 16 to 44 years, mean age 27.9 years). None of the studies used specific instruments to record aggression and violence.
Analysis of the 29 violent incidents associated with AS revealed that the most common motive was misinterpretation of the victim's intentions (10 incidents) and sensory hypersensitivity (six incidents) and that visual appearance of the victim (six incidents) and 'not getting the right response or being approached in a wrong manner by others' (five incidents) were the most common triggers of violence. Twenty-three of the violent acts were physical assaults including one murder, one attempted rape and one case of spree arson. The victims of violence were 14 females and 12 males (plus three unspecified).
Five characteristics of violence associated with Asperger's syndrome and psychopathy are compared in Table 2 indicating that there may be substantial differences between the two.
Authors' conclusions
'The evidence does not allow for firm conclusions concerning the association between Asperger's syndrome and risk for violence'.
Implications for policy or practice
Future studies should investigate the prevalence of a possible violent sub-group of those with AS and the 'possible violence prone aspects of the disorder'.