Typical Versus Atypical Antipsychotics By definition, typical antipsychotics are those which produce extrapyramidal side effects, while atypical antipsychotics do not. However, at the doses used today, most atypical antipsychotics do not produce extrapyramidal side effects. Whether typical and atypical antipsychotics differ in efficacy in a long-held debate. Except for clozapine, there are no significant differences in the efficacy of typical and atypical antipsychotics.  Two large pragmatic studies, CATIE  in the United States, and CutLASS  in the United Kingdom, in 2005 and 2006, respectively, produced similar conclusions. Another meta-analysis, in 2009 showed that risperidone, olanzapine, and amisulpride were more effective compared to typical antipsychotics.  Overall, typical antipsychotics are more likely to produce extrapyramidal side effects, while atypical ones are more likely to produce metabolic side effects, including weight gain, hyperlipemia, and diabetes.  Clozapine is mo