R ESEARCH R EPORTS D EPARTEMENT OF S OCIAL - AND C OMMUNITY P SYCHIATRY P SYCHIATRIC S ERVICES U NIVERSITY OF B ERN Zeno Kupper & Holger Hoffmann M ODELING THE D YNAMICS

There is a growing recognition of dynamical systems approaches and process oriented studies in clinical psychology and psychiatry. The new enthusiasm however risks turning into dissatisfaction when facing methodological obstacles in empirical research and mathematical modeling. Therefore graspable tools allowing a translation of current knowledge into meaningful dynamical models could be helpful as a stepping stone. In this paper a Boolean modeling approach and its application to the dynamics of psychosis is presented: Kinetic Logic, originating from R. Thomas, describes systems on an intermediate level between a purely verbal description and a description using nonlinear differential equations. A model is introduced that describes dynamical patterns of chronic psychosis in the context of vocational rehabilitation. Two attractor-like dynamics of chronicity are presented. The Boolean model also proves useful in formulating and exploring possible treatment strategies. A hypothesis about the modus operandi of family intervention is presented.