Antipsychotic drugs have usually been divided into first- and second-generation drugs with the latter being perceived as having fewer side effects than the former. Researchers from universities in Munich and Chicago looked at 150 studies comparing the effectiveness of antipsychotic drugs, which, altogether had 21,000 participants. They found that four second-generation drugs - amisulpride, clozapine, olanzapine and risperidone - were more effective than first-generation ones but that the rest were no better. When compared with the powerful first-generation drug haloperidol the second-generation drugs had less side effects but compared to other first-generation drugs there was little difference. Haloperidol - but not other first-generation drugs - produced less weight gain than most second-generation drugs. The authors called for an end to the division of drugs into first- and second-generation and an individualized treatment of schizophrenia based on efficacy, side effects and cost.
You can read more about this study at