Emotional and non-emotional mental imagery and auditory verbal hallucinations (hearing voices): A systematic review of imagery assessment tools

It is unknown to what extent mental imagery and auditory verbal hallucinations (AVHs) are related. Trials evaluating this issue used both emotional and non-emotional mental imagery tools, thereby complicating outcomes comparisons. Therefore, the present study aimed to systematically review the literature on mental imagery in individuals with AVHs to (1) inventory imagery assessment tools used in this population, (2) to collect information on the relation between emotional and non-emotional mental imagery in all sensory domains and AVHs and (3) to integrate the outcomes of this systematic review in a model of different mental imagery domains and related assessment tools. We conducted a systematic literature search in the PubMed Database. After full-text screening, 17 papers were included. Findings showed that a variety of assessment methods have been used to assess various aspects of mental imagery in people with AVHs, suggesting that there is a lack of agreed theoretical conceptualization of mental imagery and AVHs. In addition, the studies confirmed as was expected that non-emotional mental imagery seemed unrelated to AVHs whereas emotional mental imagery was related to AVHs. Lastly, we proposed a model of mental imagery domains and corresponding assessment methods distinguishing between emotional and non-emotional mental imagery.