aggression
22/03/2012
CORRELATION BETWEEN AGGRESSIVE BEHAVIORS AND PSYCHIATRIC DISORDERS IN PEOPLE WITH INTELLECTUAL DISABILITY
The relationship between aggressive behaviors and psychiatric disorders in people with and without Intellectual Disability (ID) has long been the subject of numerous studies. The scientific literature offers no conclusive explanations and often presents conflicting findings due to the use of different methodologies and population samples.
Recently, Dr. Tsiouris and his team of New York State Institute for Basic Research in Developmental Disabilities have investigated this relationship on half of the people with ID (PWID) who receive services from agencies of the State of New York, corresponding to a sample of over 4000 subjects.
Aggressive behaviors were assessed with an appropriate adaption of the Overt Aggression Scale (OAS, Yudofsky et al., 1986), called the Institute for Basic Research – Modified Overt Aggression Scale (IBR-MOAS, Cohen et al., 2010).
The IBR-MOAS has several sections. The section for the evaluation of the aggressive behaviors is then divided into 5 domains: verbal aggression towards others, physical aggression towards other, physical aggression toward objects, physical aggression and verbal aggression towards oneself
The survey results have identified the following associations: impulse control disorder with all 5 domains MOAS, bipolar disorder with all 5 domains MOAS, psychotic disorder with all domains MOAS except physical aggression against oneself (to the limit of statistical significance), anxiety disorders with physical and verbal aggression against oneself, depression with verbal aggression against oneself, obsessive-compulsive disorder with physical aggression against objects, personality disorders with verbal aggression towards others, and verbal and physical aggression towards themselves.
A statistically significant correlation was also observed between the presence of ID-autism and physical aggression toward other people, objects, and themselves.
The forms of mild to moderate ID seem to be associated with verbal aggression towards others and to themselves, while severe to profound degreeswith physical aggression towards objects and towards themselves. The female sex correlates mainly with verbal aggression towards themselves.
The authors conclude that the impulse dyscontrol, mood disorders and paranoid perception appear at the base of the most aggressive behavior.
A side but important finding for psychiatric knowledge in DI, is the tendency among evaluators to over-diagnose psychosis and major depression in the degrees of mild or moderate ID, and to under-diagnose in serious and profound degrees.
These results, in line with some previous findings, can usefully be reported in the clinical practice of the various professionals in this field.
This article has been translated and adapted to English (American) by Courtney Diamond
REFERENCES
- Tsiouris JA, Kim SY, Brown WT, Cohen IL. Association of aggressive behaviours with psychiatric disorders, age, sex and degree of intellectual disability: a large-scale survey.
J Intellect Disabil Res., 2011 Jul;55(7):636-49.
- Cohen IL, Tsiouris JA, Flory MJ, Kim SY, Freedland R, Heaney G, Pettinger J, Brown WT. A large scale study of the psychometric characteristics of the IBR Modified Overt Aggression Scale: findings and evidence for increased self-destructive behaviors in adult females with autism spectrum disorder. J Autism Dev Disord., 2010 May;40(5):599-609.
- Yudofsky SC, Silver JM, Jackson W, Endicott J, Williams D. The Overt Aggression Scale for the objective rating of verbal and physical aggression. Am J Psychiatry. 1986 Jan;143(1):35-9.
Micaela Piva Merli e Marco O. Bertelli
