Aripiprazole versus placebo for schizophrenia.

BACKGROUND First generation 'typical' antipsychotics such as chlorpromazine and haloperidol have been the mainstay of treatment up until the introduction of the second generation 'atypical' antipsychotics such as risperidone and olanzapine. Typical and atypical antipsychotics do provide a treatment response for most people with schizophrenia, whether a reduction in psychotic episodes or a lessening in the severity of their illness. However, a proportion of people still do not respond adequately to antipsychotic medication. Additionally, atypical and especially typical antipsychotics are associated with serious adverse effects, which can often compromise compliance with medication and therefore increase the incidences of relapse. In this review we examine the effects of aripiprazole compared with placebo. OBJECTIVES To evaluate the effects of aripiprazole compared with placebo for people with schizophrenia and schizophrenia-like psychoses. SEARCH STRATEGY We searched the Cochrane Schizophrenia Group Trials Register (January 2008) which is based on regular searches of BIOSIS, CENTRAL, CINAHL, EMBASE, MEDLINE and PsycINFO. For this update, we carried out an initial search in May 2007 and a second search in August 2008. SELECTION CRITERIA We included all randomised trials comparing aripiprazole with placebo in people with schizophrenia or schizophrenia-like psychosis. DATA COLLECTION AND ANALYSIS We extracted data independently. For dichotomous data we calculated risk ratios (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a fixed-effect model. We calculated numbers needed to treat/harm (NNT/NNH) where appropriate. For continuous data, we calculated mean differences (MD) again based on a fixed-effect model. MAIN RESULTS Despite the fact that 2585 people participated in nine randomised aripiprazole studies, we were unable to extract any usable data on death, service outcomes, general functioning, behaviour, engagement with services, satisfaction with treatment; economic outcomes or cognitive functioning. In general, study attrition was very large for all studies over four weeks' duration. There was high attrition in most of the included studies. Fewer people left the aripiprazole group compared with those in the placebo group (n = 2585, 9 RCTs, RR 0.73 CI 0.60 to 0.87). Compared with placebo, aripiprazole significantly decreased relapse in both the short (n = 310, 1 RCT, RR 0.59 CI 0.45 to 0.77) and medium term (n = 310, 1 RCT, RR 0.66 CI 0.53 to 0.81). It also produced better compliance with study protocol (n = 2275, 8 RCTs, RR 0.74 CI 0.59 to 0.93). Aripiprazole may decrease prolactin levels below those expected from placebo (n = 305, 2 RCT, RR 0.21 CI 0.11 to 0.37). Insomnia (˜23%) and headaches (˜15%) were commonly reported in both groups, with no significant difference. AUTHORS' CONCLUSIONS Aripiprazole may be effective for the treatment of schizophrenia. Aripiprazole has a lower risk of raised prolactin and prolongation of the QTc interval. Clearly reported pragmatic short-, medium- and long-term randomised controlled trials should be undertaken to determine its position in everyday clinical practice.