Benzodiazepines for neuroleptic-induced tardive dyskinesia

Tardive dyskinesia (TD) is a disfiguring movement disorder, often of the orofacial region, frequently caused by the use of neuroleptic drugs. A wide range of strategies have been used to help manage tardive dyskinesia, and for those who are unable to have their antipsychotic medication stopped or substantially changed, the benzodiazepine group of drugs have been suggested as a useful adjunctive treatment.

To determine the effects of benzodiazepines for neuroleptic-induced tardive dyskinesia in people with schizophrenia or other chronic mental illnesses.

1. Electronic searches. For the update of 2006, we searched The Cochrane Schizophrenia Group Trials Register (November 2005). For the previous two updates (1996, 2002) the review authors searched Biological Abstracts (1982-2002), the Cochrane Schizophrenia Group's Register of trials (February 2002), EMBASE (1980-2002), LILACS (1982-2002), MEDLINE (1966-2002), PsycLIT (1974-2002), SCISEARCH (2002), hand searched references of all included/excluded studies and contacted the first author of each included trial.

We included all randomised clinical studies focusing on people with schizophrenia (or other chronic mental illnesses) and neuroleptic-induced tardive dyskinesia that compared benzodiazepines with placebo or no intervention.

We independently extracted data from the studies and ensured that they were reliably selected, and quality assessed. For homogenous dichotomous data we calculated random effects, relative risk (RR), 95% confidence intervals (CI) and, where appropriate, numbers needed to treat (NNT) on an intention-to-treat basis. We synthesised continuous data from valid scales by using a weighted mean difference (WMD). For continuous outcomes we preferred endpoint data to change data.

We identified three trials (total N=56, one additional trial since 2002, n=24). Using benzodiazepines as an adjunctive treatment did not result in any clear changes for a series of tardive dyskinesia medium-term outcomes (n=30, 2 RCTs, RR not improved to clinically important extent 1.08 CI 0.57 to 2.05). One trial (n=24) found end point abnormal movement scores to be better for those receiving adjunct benzodiazepines(WMD AIMS -3.22 CI -4.63 to -1.81 ). Less than 10% in both groups left these studies before completion and none of the studies reported clear adverse effects.

One small study reports some preliminary evidence that benzodiazepines may have some effect in neuroleptic induced tardive dyskinesia. Inconclusive results from other studies means routine clinical use is not indicated and these treatments remain experimental.