[How to assess curative and/or preventive effects of psychotropic drugs?]

Proving the efficacy of a psychotropic drug is a medical, scientific and ethical need. Psychotropic drug development is now a highly complex process, which takes several years and which is very expensive. It involves multiple steps of preclinical and clinical pharmacological refinement and testing. Methodology of studies to prove curative or preventive effect of psychotropic drugs is well codified. Preclinical studies include pharmacokinetic data, toxicology and performance in various animal models of pathology. Clinical phases are centered on randomized controlled double blind trials for demonstrating efficacy and safety/tolerability. This methodology follows strict criteria to avoid bias and to prove internal and external validity of the results. All the results from randomized controlled trials or RCTs lead to different levels of evidence of Evidence-Based Medicine (EBM): gold standard is RCTs while the lowest reference is clinical case or expert opinion. However, it is possible to level criticism at these data issued from RCTs. The main matter is that studies do not reflect the healthcare reality in daily life. For these reasons, a real debate between evaluation of efficacy and effectiveness is acute. Effectiveness refers to the overall effects of psychotropic drugs in naturalistic conditions. Furthermore, analysis of costs and financial benefits are more and more important from social and economic points of view. Official agencies and health insurances look after them very carefully. This article deals with these issues and provides examples using data from the international literature. These examples are drawn from RCTs, naturalistic studies, meta-analysis, pharmaco-economic studies and concern neuroleptics, antipsychotics, antidepressants, and mood-stabilizers.