Evidence for the Additive Effects of Dispositional Negative Mood Regulation Expectancies and Placebo-induced Expectancies on Mood Recovery

This study investigated how NMRE and placebo-induced expectancies contribute to recovery from negative mood. Participants (N = 125) completed an online survey containing NMRE and other personality scales. During a subsequent in-person session, participants were randomly assigned to one of three conditions: (1) placebo treatment, in which participants learned of a mood-enhancing treatment and received it; (2) treatment deprivation, where participants learned of the same treatment, but did not receive it; (3) control, in which the treatment was never mentioned. Participants also completed measures of mood, active coping, and expectations. NMRE was a stronger predictor of mood recovery than general mood improvement expectancies regardless of group assignment. Additionally, pessimistic expectations arose when participants believed treatment was being deprived, and these participants exhibited the least active coping. Our results confirm the reliability of NMRE in predicting affective outcomes and suggest that personality and placebo-induced expectations have additive effects on mood recovery.