Authors:
Angé Weinrabe | Youth Mental Health Research, Brain and Mind Centre, Faculty of Medicine, The University of Sydney, NSW, 2000 Australia | Australia
Agnieszka Tymula | Faculty of Economics, The University of Sydney, NSW, 2000 Australia | Australia
Hui-Kuan Chung | Faculty of Science, Psychology Department, New York University, USA | United States
Ian. B. Hickie | aYouth Mental Health Research, Brain and Mind Centre, Faculty of Medicine, The University of Sydney, NSW, 2000 Australia | Australia
Anxious and depressed people are often characterized as irrational in common language. Underlying and contributing to “irrational” behaviour are biological and psychological substrates, such as motivation and emotion. However, in mental health care a clear definition of what it constitutes to be irrational is missing. In economics, on the contrary, irrationality in behavior is precisely defined as making intransitive choices or, violating the Generalized Axiom of Revealed Preference (GARP). Previous research has shown that young children, older adults and people with ventromedial prefrontal cortex damage show intransitivity in their choices. In this study, we extend these results by investigating whether people with severe mood disorders make economically rational choices. At two time points, separated by eight weeks, we measured subjects’ rationality using a widely used economic paradigm and we quantified the severity of subject’s mood via widely used psychological self-report scales for youth disorders (Kessler Psychological Distress K10), Quick Inventory of Depressive Symptomology QIDS-A17 and SPHERE-12). We found that help-seekers, rated as severely anxious and depressed, are more likely than those who scored lower on these scales, to make choices that violate GARP. Importantly, we found that help seekers became less irrational at round two, but that little within subject variation in mood occurred.
Decision-making | rationality | depression | anxiety | affect | emotion