Prevalence, phenomenology, aetiology and predictors of challenging behaviour in Smith-Magenis syndrome.

Background: The prevalence, phenomenology aetiology and correlates of four forms of challenging behaviour in 32 children and adults with Smith-Magenis syndrome (SMS) were investigated.
Methods: Cognitive assessments, questionnaires and semi-structured interviews were used to gather data on intellectual disability, verbal and physical aggression, destructive behaviour and self-injury and on characteristics known to be associated with aggression.
Results: Aggression in SMS was more prevalent (87%), but not more severe than aggression in contrast groups. Aggressive behaviour was more frequently associated with environmental contingencies (e.g. attention, escape and access to tangibles) than self-injury and destructive behaviours. Severity of challenging behaviours was associated with high impulsivity.
Conclusion: Aggression is seen in the majority of people with SMS. Results suggest that behavioural disinhibition and operant social reinforcement are associated with the manifestation of aggression.
(© 2011 The Authors. Journal of Intellectual Disability Research © 2011 Blackwell Publishing Ltd.)