Ethical Problems and Design of Controlled Clinical Trials

Abstract

Psychiatry is rather far away from the therapeutic ideal (Ehrlich’s therapia magna sterilisans): to achieve immediate and complete success in all patients with the disease for which the therapy is indicated (specific efficacy) with no undesired side effects (safety). Currently available psychiatric therapies achieve at best only moderate specific efficacy and safety, so therapy research in psychiatry is badly needed. The main tool for this is the controlled clinical trial. However, the vast number of trial types and designs indicates that there is no ideal for all questions, but only designs which are more or less appropriate for a specific question. Furthermore, a controlled clinical trial goes beyond the individual’s therapeutic help insofar as it is an experimental procedure for gaining new knowledge and a more rational basis for improvement of therapy. According to the Helsinki/ Tokyo Declaration this means a greater need for getting valid informed consent than in routine therapy. However, it is precisely from patients with psychiatric disorders that informed consent may be a particular problem. Although some psychiatric disorders may destroy the capacity of a patient to understand a given piece of information and to give valid consent, all psychiatrists know that this is, in contrast to common public opinion, by no means true of all psychiatric patients. Rather, in a considerable number of psychiatric patients the competency for full informed consent is reduced only transiently and/or partially, and in other patients full competency is maintained (Fletcher et al. 1985; Helmchen 1986a,b; Helmchen and Winau 1986).