LAUSR

BACKGROUND AND OBJECTIVES Depressed people hold positive beliefs about negative cognition (e.g., rumination is useful to find a solution), which may motivate those individuals to engage in sustained negative thinking. However, in reality, rumination often leads to unfavorable outcomes. Thus, such beliefs create a large discrepancy between one's expectations and the actual outcome. Therefore, we hypothesized that this prediction error would be associated with increased depressed mood. METHODS We observed how people update their positive beliefs about negative cognition within a volatile environment, in which negative cognition does not always result in a beneficial outcome. Forty-six participants were offered two response options (retrieving a negative or positive personal memory) and subsequently provided either an economic reward or punishment. Retrieving a negative (rather than positive) memory was initially reinforced, although this action-outcome contingency was reversed during the task. In the control condition, positive memory retrieval was initially reinforced, although a contingency reversal was employed to encourage negative memory retrieval. RESULTS Model-based computational modeling revealed that participants who showed a delay in switching from negative to positive (but not from positive to negative) responses experienced increased levels of depressed mood. This delay in switching was also found to be associated with depressive symptoms and trait rumination. LIMITATIONS The non-clinical nature of the sample may limit the clinical implications of the results. CONCLUSIONS Difficulty in updating positive beliefs (or outcome predictions) for negative cognition may play an important role in depressive symptomatology.