A new UK study found that placebo was just as effective at treating aggressive challenging behaviour in intellectually disabled patients as antipsychotic drugs and the researchers recommended antipsychotics no longer be regarded as an acceptable routine treatment for this group.

The study is published in the January 5th issue of The Lancet and is the work of Peter Tyrer, professor of Community Psychiatry Division of Neurosciences and Mental Health, at the Department of Psychological Medicine, Imperial College, London, UK, and colleagues.

Antipsychotic drugs are often used to treat adults with intellectual disability (having an IQ below 75) who present with aggressive challenging behaviour, wrote the researchers. This is despite there being insufficient convincing evidence to support such practice.

In this study Tyrer and colleagues compared the effectiveness of treating this behaviour with flexible doses of a typical first generation antipsychotic, haloperidol, an atypical second generation antipsychotic, risperidone, and a placebo.

The participants were patients from ten centres in England and Wales, and one in Queensland, Australia. All 86 patients were non-psychotic adults showing aggressive challenging behaviour. They were enrolled in a trial called the Neuroleptics for Aggressive Challenging Behavior in Intellectual Disability study.

The patients were randomnly assigned to one of three drug groups: 28 to the haloperidol, 29 to the risperidone, and 29 to the placebo group.

The researchers took a range of measurements at 4, 12 and 26 weeks after treatment began. The measurements were taken by telephone interview with the patients’ carers. They included: clinical assessments of aggression and aberrant behaviour, quality of life, adverse effects of the treatment, carer uplift (how the carer felt about the care of their patient), carer burden, and costs.

The change in aggression after 4 weeks of treatment was the main outcome measure, based on a scale called the modified overt aggression scale (MOAS).

The results showed that:

  • 80 per cent of the patients stuck to at least 80 per cent of the treatment (drug adherence).
  • Aggression, as measured by the MOAS scale went down significantly in all three groups at week 4.
  • The largest decrease was in the placebo group which showed a median MOAS decrease of 79 per cent from baseline.
  • This compared with 58 per cent for risperidone and 65 per cent for haloperidol.
  • There were no important differences among the treatments, including adverse effects.
  • Responses for patients in the placebo group were no worse, at any time, than responses for patients in either of the drug groups.

The study concluded that:

“Antipsychotic drugs should no longer be regarded as an acceptable routine treatment for aggressive challenging behaviour in people with intellectual disability.”

An accompanying editorial supported Tyrer and colleagues’ conclusion, that the practice should come to an end, especially in routine giving of the drugs to children. But while it was “a worthy goal”, in practice it will not be easy, wrote Johnny L Matson and Jonathan Wilkins from Louisiana State University.

However, the researchers said there may still be a place for such drugs in particular circumstances and groups. For example they may be appropriate for treating autistic behaviour in children or if the drugs are given in an emergency, it may be necessary to continue with them to prevent further aggressive behaviour.

“Risperidone, haloperidol, and placebo in the treatment of aggressive challenging behaviour in patients with intellectual disability: a randomised controlled trial.”
Peter Tyrer, Patricia C Oliver-Africano, Zed Ahmed, Nick Bouras, Sherva Cooray, Shoumitro Deb, Declan Murphy, Monica Hare, Michael Meade, Ben Reece, Kofi Kramo, Sabyasachi Bhaumik, David Harley, Adrienne Regan, David Thomas, Bharti Rao, Bernard North, Joseph Eliahoo, Shamshad Karatela, Anju Soni, Mike Crawford.
The Lancet, Vol. 371, Issue 9606, 5 January 2008, Pages 57-63.
DOI:10.1016/S0140-6736(08)60072-0

Click here for Abstract.

“Antipsychotic drugs for aggression in intellectual disability.”
Johnny L Matson, Jonathan Wilkins.
The Lancet, Vol. 371, Issue 9606, 5 January 2008, Pages 9-10.

Click here for full text of Article (subscribers only).

Written by: Catharine Paddock