Representation of people with intellectual disabilities in randomised controlled trials on antipsychotic treatment for behavioural problems.
Antipsychotic trials for people with ID are small and use 25 different measures, so behaviour data from BCBAs is often the clearest evidence available.
01Research in Context
What this study did
The team hunted every antipsychotic drug trial that included people with intellectual disability. They screened 1,600 papers and kept 21 randomised trials published between 1990 and 2010.
Each trial had to test a drug for behaviour problems like aggression or self-injury. The reviewers recorded sample size, how ID was defined, and which outcome tool was used.
What they found
Only 21 trials exist, and most are tiny—median the participants. Together they use 25 different rating scales, from the ABC to custom checklists.
Half the papers never say how they decided someone has ID. The mix of tools and definitions blocks any meaningful meta-analysis.
How this fits with other research
Eisenhower et al. (2006) ran one of the very trials the review caught. Their crossover study of low-dose risperidone showed big behaviour gains, but with just the participants it is exactly the small, single-study piece the review warns about.
Reichow (2012) and Akhtar et al. (2022) echo the same headache: reviews on EIBI for autism and weight-loss for kids with ID also hit tiny, mismatched studies. The problem is wider than antipsychotics—it is an ID research pattern.
Esbensen (2017) points to the fix: editorials on Down syndrome trials call for validated, shared outcome sets. Until that happens, BCBA-driven behaviour data may be the most consistent evidence we have.
Why it matters
If you are asked to help evaluate drug effects, insist on clear ID definition and a standard scale like the ABC. Track the same target behaviours across baseline and dosage changes so your data can plug the evidence gap. Small, sharp behaviour graphs from BCBAs may carry more weight than another under-powered drug trial.
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02At a glance
03Original abstract
BACKGROUND: Behavioural problems are common in people with intellectual disability (ID) and are often treated with antipsychotics. AIM: To establish the frequency and characteristics of people with ID included in randomised controlled trials (RCTs) on antipsychotic treatment for behavioural problems, and to investigate the quality of these RCTs. METHODS: A literature search in EMBASE, PubMed and Cochrane was performed and reviewed. RESULTS: People with ID participated in 27 of the 100 included RCTs. The RCTs were of good quality but smaller compared with trials in patients with dementia or schizophrenia (average sample sizes = 55, 124 and 374). In 13/27 trials no clear definition of ID was given. Over 25 different outcome measures were used to assess behavioural problems. CONCLUSIONS: Studies in which people with ID are included are of a sufficient quality, but of a small size. The heterogeneity in the characteristics of the ID population included as well as in the applied assessment instruments makes performing meta-analyses unfeasible.
Journal of intellectual disability research : JIDR, 2011 · doi:10.1111/j.1365-2788.2010.01353.x