Is evidence sufficient for evidence-based medicine?

Psychopharmacotherapy should now be regulated in the sense of evidence-based medicine (EBM), as is the case in other areas of clinical treatment in medicine. In general this is a meaningful development, which will principally have a positive impact on routine health care in psychiatry. But several related problems should not be ignored. So far consensus on an internationally accepted evidence graduation could not be reached, due to several difficulties related to this. A principle question is also whether it is sufficient to base EBM primarily on the results of phase III trials with their high internal validity. Restrictions to generalise findings of phase III trials suggest the need for additional sources of evidence, amongst others "effectiveness" studies and other kinds of phase IV studies with their less restrictive methodological standards. Attempts to regulate psychopharmacotherapy in the sense of evidence-based medicine come closer to their limits the more complex the clinical situation and the respective decision-making logic are. Even in times of evidence-based medicine we are faced with the situation that a large part of complex clinical decision-making in psychopharmacotherapy still relies more on personal clinical experience and a group consensus about clinical experience, traditions and belief systems than on results of efficacy oriented phase III and effectiveness-oriented phase IV clinical studies.