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.