The effect of positive mental imagery versus positive verbal thoughts on anhedonia.

Anhedonia, the loss of interest in and pleasure from previously enjoyable activities is a core symptom of depression and presents a major challenge to treatments. Interventions involving positive mental imagery generation have been suggested to reduce anhedonia. However, it is not clear whether the imagery component of such interventions is crucial for these effects. The current study aimed to test this by contrasting repeated generation of positive mental imagery versus positive verbal thoughts. Over a one-week period, 53 mildly anhedonic adults completed five sessions of a computerized training program involving the generation of either positive images or positive sentences. Compared to participants who generated sentences, participants who generated imagery showed greater improvements from pre- to post-training on an individualized multi-facetted measure of anhedonia (the Dimensional Anhedonia Rating Scale), but not on standardized measures of anticipated pleasure (the Snaith-Hamilton Pleasure Scale), depression symptoms, or positive affect. The present study supports the proposal that positive imagery could provide a route to improve anhedonia, with generation of imagery in particular (as opposed to positive thoughts in general) as an important driving mechanism for these effects. This has theoretical and clinical implications for understanding the role of imagery in anhedonia and its treatment.