[Clinical trials using antidepressants and antipsychotics. The pros and cons of placebo control]

Controlled, randomized, double-blind, parallel group clinical trials are needed to establish efficacy and safety of new psychopharmacological drugs. Usually this is done by clinical trials including placebo control. These placebo-controlled trials have been criticized as being unethical in clinical situations where effective and acceptable treatment options are available. It has been argued that studies with potential new antidepressants or antipsychotics should employ only a comparator-controlled design, whereby new drugs have to be non-inferior or superior to existing treatment. In general actively controlled designs require the inclusion of larger patient populations. However, sole acceptance of "superior" compounds will hinder the development of more efficacious and better tolerated drugs. Moreover, acceptance of non-inferiority designs in psychopharmacology will be associated with the risk of ineffective compounds being approved. Due to these methodological reasons placebo-controlled studies of new antidepressants and antipsychotics are still justified and necessary, both ethically and scientifically. Therefore, from a regulatory point of view three-arm studies including standard, new drug and placebo represent the preferred study design, which allows the most comprehensive interpretation of study results. However, measures should ensure that patients are not harmed by the act of forgoing established treatment options and that they provide fully informed consent. The article reviews the methodological and ethical rationale for conducting placebo-controlled trials with antidepressants and antipsychotics.