The research network comprises 16 closely linked projects. This integration of projects and teams enables research questions to be examined from several perspectives in order to obtain answers at different levels. What are the neurobiological and psychological mechanisms that underlie the effects of treatment expectation? And how do we explain individual differences? To answer this question, large quantities of data must be analysed. That is why two central research projects (identified by project number Z) analyse data from across the network. Can these findings be used to benefit patients? For which diseases? Clinical studies can provide clarity here, and we focus initially on two common conditions: chronic pain (pain system) and depression (affective system).