[Farewell to the dodo-bird: specific versus general psychotherapy from the perspective of psychotherapy research].

Based upon different specificity problems in psychotherapy, it is shown that psychotherapy research consists of two different worlds, the one focussing on disorder specific factors, the other traditionally investigating unspecific or common therapeutic factors. Relating to the Dodobird verdict that has been used to describe the so-called equivalence paradox in psychotherapy, several views of common therapeutic factors are summarized. Recent research shows that psychotherapy research also indicates a specificity paradox that can be resolved by the observation that several psychological disorders develop their own dynamics and that--besides this--general principles are active. In several settings and in relation to specific disorders both aspects have already been integrated successfully.