Characteristics of memories of delusion-like experiences within the psychosis continuum: Pilot studies providing new insight on the relationship between self and delusions

Background and objectives: Delusions are usually anchored in past events associated with abnormal experiences or delusional interpretations of personal events. The characteristics of the memory of these experiences may contribute to maintain delusional beliefs by providing confirmatory evidence for the delusions. However, these aspects have not been investigated properly. Method: Seventeen patients with schizophrenia were examined in study 1 during a face-to-face interview. The second study used a web-based design and included 83 participants without a psychotic disorder. Participants were asked to rate the vividness, emotional intensity and valence, and the centrality to the self of memories of delusion-like experiences (that were cued by means of the Peters et al. Delusional Inventory, PDI; Peters, Joseph, Day, & Garety, 2004) and positive and negative memories used as comparators. Results: In both studies, the memories of delusion-like experiences were less vivid, less emotionally intense than positive (but not negative) memories and emotionally neutral. Their centrality to the self did not differ from that of positive and negative memories. Moreover, the severity of delusions in study 1 and delusion-proneness in study 2 were significantly correlated with vividness, emotional intensity, and centrality of memories of delusion-like experiences. Limitations: The accuracy of memories of delusion-like experiences could not be checked making it difficult to distinguish them from delusional memories. The sample size was small in study 1. Conclusions: Our results point to reciprocal relationships between delusions, self, and autobiographical memories of delusion-like experiences that are similar within the psychosis continuum and that may be involved in the maintenance of delusions. (C) 2016 Elsevier Ltd. All rights reserved.