What does clinical research in psychosomatics imply?

As animal experiments are no adequate substitute, clinical research in psychosomatics is indispensable. In this domain the complexities of the human mind engender a host of pitfalls. Five of these are illustrated by concrete examples, and countermeasures are discussed. Patient selection processes must be evaded by field studies or be elucidated and described carefully. Observer influence is circumvened by non-obtrusive measurement or by keeping subjects 'naive'. The choice of variables to be studied is an open-ended venture. Instead of adhering to the homogeneity myth, we should search for clinically relevant subgroups. The post-propter problem needs more prospective studies.