Occurrence, nature, impact and possible causal mechanisms of hallucinations across sensory modalities in people with an ultra-high risk of psychosis.

OBJECTIVES

Studies of unusual sensory experiences, like hallucinations, in people at risk of psychosis usually focus on auditory experiences. This study explored how common experiences across a range of sensory modalities were in people at an ultra-high risk of developing psychosis. Particular attention was paid to the number of modalities reported and their impact. It was hypothesised that people reporting a greater number of modalities of hallucinations would report greater levels of general distress, more delusional ideation, lower emotional well-being and poorer functioning. In addition, the contribution of sleep problems and post traumatic stress disorder (PTSD) symptoms in the reporting of hallucinations in different modalities was explored.

DESIGN

A single-group cross-sectional design was used.

METHODS

People at an ultra-high risk of developing psychosis completed measures of hallucinations, delusions, general distress, functioning, emotional well-being, trauma and sleep.

RESULTS

Nearly all participants reported hallucinations in the auditory domain. They also reported a range of other unusual sensory experiences, with visual and somatic/tactile hallucinations being reported by over half. Single sensory experiences or unimodal hallucinations were less common than hallucinations in two or more modalities, which were reported by 88% of the participants. The number of modalities of hallucinations was significantly associated with greater general distress, delusional ideation, reduced emotional well-being and to some extent functioning. PTSD and sleep were identified as potential causal factors for hallucinations across modalities.

CONCLUSIONS

Psychological therapies need to account for these experiences and could feasibly target them with treatments that focus on sleep or trauma.