Aggressive Behaviour in Adults with Intellectual Disability

A complex form of aggression, commonly expanded as ‘aggressive challenging behaviour’, is reported in one in four adults with intellectual disability and is often treated with antipsychotics, mood stabilizers and antidepressants. Psychological treatments, including anger and behavioural management, person-centred planning and manipulation of the environment (nidotherapy), have also been used when available but to a lesser extent. In this article, the evidence for efficacy for each intervention is examined, with data from randomized controlled trials given primacy. Very little evidence, based on limited data, can be found for the interventions of anger and behavioural management and also for the atypical antipsychotic drug, risperidone; the data available on these interventions come primarily from studies conducted in children in whom the behaviour is part of the autistic spectrum. Antipsychotic drugs, particularly the atypical group, have been the most commonly used interventions in recent years, but a recent independent randomized trial showed no benefits for either risperidone or haloperidol compared with placebo, with some evidence of a better response to placebo than either active drug in the reduction of aggression.

In the light of this uncertainty, the clinician must return to the task of collecting a careful history and mental state examination, including awareness of the setting in which the behaviour is shown, which will help with diagnosis and appropriate intervention. The choice of intervention should not be a casual one and is not likely to be chosen well if the clinician relies only on standard guidelines.

The paucity of randomized trial evidence is preventing progress in the treatment of persistent aggressive behaviour. On present evidence, the use of drug treatment should be much more sparing and reserved for those patients who are putting themselves and others at particular risk as a consequence of their behaviour; such treatment should be regarded as temporary and as adjunctive to other forms of management. There is an urgent need for larger, randomized studies of psychological interventions, which at present appear to have a higher benefit-risk ratio than drug treatment but that also have a poor evidence base. More care should be taken to avoid the term ‘aggressive challenging behaviour’ being used as a portmanteau diagnostic pseudonym when it merely represents a diverse oppositional repertoire of many aetiologies.