Charles Bonnet Syndrome: associations between psychosocial measures and visual hallucination characteristics in the...

The emotional response to Charles Bonnet Syndrome (CBS) (visual hallucinations in individuals with sight loss) is associated with negative affect, suggesting a link between psychological measures and hallucination characteristics. This study set out to investigate whether the association extends to a broader range of hallucination attributes and psychological measures, taking into account clinical factors likely to influence such associations.

70 participants with self-reported CBS completed an online survey assessing hallucination attributes of frequency, duration, emotional valence, distress, level of control over hallucinations and impact on quality of life (QoL). Anxiety and depression were measured using the Hospital Anxiety and Depression Scale while loneliness was assessed using the University of California Los Angeles (UCLA) Loneliness Scale. All three measures were combined as a mental health factor. Regression models tested relationships between hallucination attributes and mental health, controlling for age, sex assigned at birth, years of sight loss, years experiencing hallucinations, presence of migraine and visual field loss.

All visual hallucination attributes except level of control were associated with the mental health factor; higher factor scores were associated with more frequent, longer lasting, more unpleasant and more distressing hallucinations and also with a more negative impact of hallucinations on QoL. These associations were independent of years of sight loss and CBS.

Mental health measures are linked to a wider range of CBS attributes than previously recognised, with greater clinical attention required to identify people with CBS who are experiencing psychological difficulties to help provide appropriate treatment and support.

The study did not include a control group of visually impaired participants without hallucinations and has an uneven representation across age and gender with a small sample size for the sub-group analysis. The study relied on self-reported online data without clinical assessment; details of participants' medication use were not collected.