The objectification of treatment efficacy becomes essential for the medical as well as economic reasons (rationale for the choice and evidence of efficacy). When choosing an option, it is necessary to take into consideration current knowledge and to treat according to current guidelines. The development of new psychotropic drugs leads to the necessity to prove sofistically their efficacy. When the guidelines are made, the evidence-based methods are preferred. Psychotropic medications do fulfill this requirement. Their efficacy was proved in randomised, controlled, double-blind trials. Observation studies have lower power of evidence, but they can often be complementary to the randomised controlled trials. The e-STAR study with a mirror design is an example of concurrent observation study that records the results of the treatment with a new intramuscular longlasting atypical antipsychotic agent comparing it with previous treatment. At the same time, the monitoring of parameters that are a part of the common clinical practice, including remission, enables us to evaluate more objectively the effect of long time treatment.

        Key words: objectiation of treatment efficacy, treatment algorithms, observation study, complementary study, e-STAR study.