Effect of Positive Mental Imagery Stimuli on Anhedonic Depressive Symptoms

Abstract

This study aimed to investigate the effect of the intervention of positive mental imagery on anhedonia and the underlying reward mechanism in depression, and to explore the sustainability of the impact of the intervention following stress induction. Participants reporting anhedonic depressive symptoms (N=54) were randomly assigned to either a positive mental imagery condition or a verbalization condition, the former utilizing positive imagery stimuli only, and the latter utilizing language-based on meaning. Participants in both the conditions completed a computerized picture-word task for imagery generation and mental arithmetic stress task for stress induction. The results showed that both intervention conditions significantly reduced anhedonia and negative affect and that the mental imagery intervention was not superior to verbalization intervention. After stress induction, there was no significant difference between the two conditions in terms of the sustainability of the impact of the intervention on mood, reward subcomponents, and anhedonia. These findings provide preliminary evidence of the effectiveness of positive mental imagery in improving anhedonia. Furthermore, this study emphasizes the importance of repetitive imagery intervention due to the unsustainable impact of brief interventions after stress induction.