Decision-making and delusion. A study on decision-making in deluded, depressive and healthy subjects

Delusion as a phenomenon was always in the focus of psych iatric interest. Explanations for its origin reach from disturbed perception or affect to de ficits in cognition. In our study we investigated 20 deluded, 20 depressive and 20 healthy subjects in order to find out differences in decision makin g, while a neutral test situation. Our hypothesis was that deluded subjects need less information for decision making and tend less to change their de cision, ma de before, than both control groups will do this. For examinatio n our hypothesis a modified version of "Probabilistic Inference Task" by Ph ilips and Edwards was performed. In summary we found that deluded subjects need less information for decisions making than the control groups. Further more, decision making of deluded subjects seems more impulsive and less ref erring to formal logical criteria than it was found in depressed and health y volunteers.