So-called 'second-generation' antipsychotic drugs have traditionally been seen as providing the same level of effectiveness as first-generation ones with far fewer side effects. However, comparisons have usually been made with a highly potent first generation drug such as haloperidol. Researchers at the University of New Mexico, U.S. looked at trials which compared second-generation antipsychotics with less powerful first-generation ones and found that the effectiveness and side effects of the two types of drugs were comparable. The authors of the study concluded that clinicians should look at the unique pharmacological and side effect profile of each drug before making prescribing decisions.
Bonham, Caroline and Abbott, Christopher - Are second generation antipsychotics a distinct class? Journal of Psychiatric Practice July 2008, 14(4), 225-231