Introduction: Antipsychotics are the most widely prescribed drugs in people with intellectual disability even if schizophrenia and other psychotic disorders do not affect more than 3% of such population. Many authors outline the lack of studies on the efficacy of antipsychotics on schizophrenia or other psychotic disorders in people with intellectual disability.
Materials and methods: The aim of the present study is to review all evidences resulting from international trials selected by Medline, and compare efficacy and side effects of different antipsychotics in people with both intellectual disability and psychotic disorders and/or behavioural disorders.
Results: 195 studies were identified; 117 concern traditional antipychotics while 78 new generation ones. If we consider the type of studies, it results that only the 12.8% of all production is represented by meta-analyses, systematic reviews, and randomised and not controlled trials.
Conclusions: Randomised controlled trials and systematic reviews would be the golden standard for therapeutical studies; unfortunately they are really few in this field. It is anyway significative that all the studies reported focus on the use of antipsychotics in people with intellectual disability presenting behavioural problems. To increase the validity of these studies it is recommendable to proceed only with well-designed studies, possibly double-blind versus placebo or other medications. There is need to define precise inclusion criteria, precise symptomatological or behavioural targets and adaptative ability assessment, using valid and reliable diagnostic instruments.