[Pharmacologic and clinical properties of a new butyrophenone derivative (FR 33)]

Antipsychotic medication versus placebo for people with both schizophrenia and learning disability

BACKGROUND

Antipsychotic medication is the standard treatment for people with learning disability and schizophrenia.

OBJECTIVES

To determine the effects of any antipsychotic medication compared with placebo for treating people with a dual diagnosis of learning disability and schizophrenia.

SEARCH STRATEGY

For this update we searched the Cochrane Schizophrenia Group's Register of trials (July 2004), relevant reference lists and sought unpublished data from pharmaceutical companies.

SELECTION CRITERIA

We included all randomised clinical trials of longer than one month's duration, involving people with both schizophrenia and learning disability (a measured IQ of 70 or less) that evaluated antipsychotic medication versus placebo.

DATA COLLECTION AND ANALYSIS

We reliably selected and assessed studies for methodological quality. Two reviewers, working independently, extracted data. We would have analysed dichotomous data on an intention-to-treat basis and presented continuous data with 65% completion rate. For dichotomous outcomes, our intention was to estimate a fixed effect relative risk (RR) with the 95% confidence interval (CI) together with the number needed to treat/harm (NNT/H).

MAIN RESULTS

We found only one relevant randomised trial using our search method and this had to be excluded. This study included four people with a dual diagnosis of schizophrenia and learning disability, but results were only available for two of the participants. It was unclear as to which groups the other two people were allocated. In order to display the data, we would have had to have made too many assumptions about these two people and any results would be uninformative and potentially misleading.

REVIEWERS' CONCLUSIONS

Using the methods described we found no randomised controlled trial evidence to guide the use of antipsychotic medication for people with both learning disability and schizophrenia. Until the urgent need for randomised controlled trials is met, clinical practice will continue to be guided by extrapolation of evidence from randomised controlled trials involving people with schizophrenia, but without learning disability, and non-randomised trials of those with learning disability and schizophrenia.

Antipsychotic medication for those with both schizophrenia and learning disability

BACKGROUND

Antipsychotic medication is the standard treatment for people with learning disability and schizophrenia.

OBJECTIVES

To determine the efficacy of any antipsychotic medication for treating people with a dual diagnosis of learning disability and schizophrenia.

SEARCH STRATEGY

Electronic searching of Biological Abstracts, the Cochrane Schizophrenia Group's Register of trials, the Cochrane Library, EMBASE, PsycLIT and MEDLINE. Unpublished data were sought from pharmaceutical companies. Both authors independently selected the relevant studies from the reports identified in this way.

SELECTION CRITERIA

1. All randomised controlled trials of antipsychotic medication, regardless of dosage, versus a placebo control, of longer than one month's duration. 2. Anyone over 18 years of age with both learning disability and schizophrenia. Learning disability was defined as a measured IQ of 70 or less. Any mode of diagnosis of schizophrenia was acceptable.

DATA COLLECTION AND ANALYSIS

The two reviewers independently attempted to select and then extract data but it was not possible to do this with the single study that met the inclusion criteria.

MAIN RESULTS

Only one relevant randomised trial was found by the searches. This study included four people with a dual diagnosis of schizophrenia and learning disability, but results were available for only two. The groups to which the other two people were allocated were unclear. In order to display the data, too many assumptions would have to have been made about these other two people and any results would be uninformative and potentially misleading.

REVIEWER'S CONCLUSIONS

Using the methods described the reviewers found no randomised controlled trial evidence to guide the use of antipsychotic medication for those with both learning disability and schizophrenia. Until the urgent need for randomised controlled trials is met clinical practice will continue to be guided by extrapolation of evidence from randomised controlled trials involving people with schizophrenia but without learning disability and non-randomised trials of those with learning disability and schizophrenia.

Effectiveness of antipsychotic medication in people with intellectual disability and schizophrenia: a systematic review

The aim of the present study was to determine the efficacy of any antipsychotic medication for treating people with a dual diagnosis of intellectual disability and schizophrenia. The authors performed an electronic search of Biological Abstracts, the Cochrane Schizophrenia Group's Register of trials, the Cochrane Library, EMBASE, PsycLIT and MEDLINE. Unpublished data were sought from pharmaceutical companies. Both authors independently selected the relevant studies from the reports identified in this way. Only one relevant randomized trial was found by the searches (Foote 1958). This study included four people with a dual diagnosis of schizophrenia and intellectual disability, but results were only available for two subjects. The groups to which the other two people were allocated were unclear. Using the methods described, the reviewers found no trial evidence to guide the use of antipsychotic medication for those with both intellectual disability and schizophrenia. Until the urgent need for randomized controlled trials is met, clinical practice will continue to be guided by evidence from trials involving people with schizophrenia but without intellectual disability.